INTRODUCTION — Pyoderma gangrenosum (PG) is an uncommon inflammatory and ulcerative skin disorder characterized histopathologically by the accumulation of neutrophils in the skin. The most common presentation of PG is the rapid development of one or more painful, purulent ulcer with undermined borders on sites of normal or traumatized skin.

Although multiple local and systemic therapies have been utilized for PG, high-quality efficacy studies are lacking for most interventions. Topical and systemic corticosteroids, topical tacrolimus, and systemic cyclosporine are among the most commonly utilized pharmacologic agents.

The management and prognosis of PG will be reviewed here. The pathogenesis, clinical features, and diagnosis of PG are reviewed separately. (See "Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis".)

APPROACH TO TREATMENT — The careful exclusion of other disorders that may cause cutaneous ulceration is an important first step in the management of lesions that appear consistent with pyoderma gangrenosum (PG). This is of particular importance since certain therapies utilized for PG can be ineffective or harmful in other diseases. (See "Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis", section on 'Diagnosis' and "Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis", section on 'Differential diagnosis'.)

As a result of the paucity of data on interventions for PG, definitive guidelines for patient management are lacking. The approach to the treatment of PG is primarily guided by small uncontrolled studies and clinical experience. In general, patients are managed with a combination of topical and/or systemic therapies that suppress the inflammatory process and wound care measures that optimize the environment for wound healing. Although initial signs of improvement may be evident within days of the start of treatment, weeks to months are often required to achieve complete ulcer healing [1,2].

For patients with mild PG (few superficial ulcers or vegetative PG), the local administration of corticosteroids or a calcineurin inhibitor can be sufficient for treatment. In contrast, systemic therapy is typically necessary in patients with more extensive PG. Glucocorticoids are the most common systemic drugs prescribed since a rapid response is often observed, and the drugs are relatively low in cost and are easily administered. Systemic cyclosporine is an alternative first-line treatment for patients who cannot tolerate systemic glucocorticoid therapy.

A wide variety of other systemic immunomodulatory drugs can be utilized as alternative or adjunctive treatments for PG that fails to respond sufficiently to first-line therapies. Examples include biologic drugs, conventional immunosuppressants, dapsone, and minocycline. Infliximab has demonstrated efficacy for PG in a randomized trial, and its concomitant utility in Crohn's disease favors the use of this drug in patients with both diseases. In patients with mild PG that is resistant to local therapy, we often prescribe a trial of dapsone or minocycline, which are generally well tolerated, prior to treatment with immunosuppressive therapies [3]. Intravenous immune globulin (IVIG) and alkylating agents are treatment options that are typically reserved for patients with severe, refractory disease [3].

PG frequently occurs in association with other medical disorders, most commonly inflammatory bowel disease, hematologic malignancy, and arthritis. Although the course of the disease does not always parallel PG, treatment of the associated disorder sometimes results in improvement in PG. (See "Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis", section on 'Associated disorders' and 'Prognosis' below.)

The treatment options for PG are reviewed below.

FIRST-LINE THERAPY — As noted above, the severity of pyoderma gangrenosum (PG) influences the choice of initial therapy. Although local interventions successfully induce healing in some patients with mild disease, patients with more extensive PG require systemic therapy to arrest disease activity. Documentation of the size, number, and location of ulcers and serial clinical photographs are useful for following the response to therapy.

Wound management — The goal of wound care in PG is to create an optimal environment for wound healing.

Local care — Wounds should be cleansed gently with tepid sterile saline or a mild antiseptic prior to dressing changes [2]. Wound dressings that promote a moist wound environment and do not adhere to the wound base are preferred, as they may be beneficial for healing [4]. (See "Basic principles of wound management", section on 'Importance of moisture'.)

The selection of a specific type of wound dressing depends on the nature of the wound and patient and clinician preferences. As an example, patients with wounds that are highly exudative may benefit from the use of more absorptive wound dressings, such as alginates to avoid tissue maceration [3]. (See "Basic principles of wound management", section on 'Wound dressings'.)

Pathergy (exacerbation of lesions at sites of trauma) can occur in PG. Thus, unnecessary traumatic insults to the wound, such as the use of wet to dry dressings and the application of caustic substances (eg, silver nitrate) should be avoided [2,3]. (See "Pyoderma gangrenosum: Pathogenesis, clinical features, and diagnosis", section on 'Clinical manifestations'.)

In addition to the area of ulceration or erosion, attention should also be paid to the surrounding skin. Use of a barrier cream or ointment, such as zinc oxide paste or petrolatum, may help to prevent skin breakdown at the wound edge [3,4]. Patients should be monitored for clinical signs of wound infection (eg, fever, warmth, swelling, malodor, lymphangitic streaks, increased drainage, or pain), and should be treated appropriately with antibiotics if infection occurs [3]. Hyperbaric oxygen has been reported to be of benefit for wound healing in a few patients with PG, but data are insufficient to recommend the routine use of this therapy [5-7].

Surgery — Due to the potential for pathergy, the role of surgery for wound management in PG is controversial [8,9]. Surgical procedures are considered only in select cases, such as those in which accumulation of necrotic tissue presents a risk for infection or where vital tissues such as tendons or ligaments are exposed in the ulcer bed [10,11]. Although multiple cases in which PG worsened following surgical intervention have been reported [1,9], documentation of cases in which gentle debridement, skin flaps or grafts [12-15], split thickness grafts with negative pressure wound therapy [16], and the application of bioengineered keratinocyte autografts [17] or allogenic cultured dermal substitutes [18] appeared to be beneficial in PG exists. To minimize the likelihood of pathergy, performance of surgical procedures should be limited to periods of good disease control, and patients should be concomitantly treated with systemic therapy [8].

Although stoma closure can lead to resolution of peristomal PG, recurrence of PG may be common after relocation or revision of a stoma. In a retrospective chart review of 44 patients with peristomal PG, 10 of 15 patients (67 percent) who underwent relocation or revision of a stoma developed recurrent PG [19].

Limited disease — Local interventions can be used as initial therapy in patients with mild, localized PG (eg, few superficial ulcers or vegetative PG). When effective, local treatment is preferred due to the relatively low risk of serious adverse effects. The most common interventions utilized are topically or intralesionally administered corticosteroids and calcineurin inhibitors. Local therapy should be delivered to the ulcer's inflamed periphery.

No randomized trials of topical or intralesional therapies for PG have been performed, and additional studies are necessary to determine the best approach to local management. We typically utilize a superpotent topical corticosteroid (eg, clobetasol 0.05% ointment) as initial therapy. Improvement is usually evident within two to three weeks. In patients who fail to demonstrate improvement with a superpotent topical corticosteroid within this time period, we attempt treatment with tacrolimus 0.1% ointment or systemic therapy.

Local corticosteroids — Although topical corticosteroids are frequently prescribed as primary and adjunctive therapies in PG, data on the efficacy of these agents are limited to a few retrospective studies and case reports [10,20]. High potency or superpotent topical corticosteroids, such as clobetasol propionate, are usually applied once or twice daily (table 1). A multicenter prospective cohort study that evaluated outcomes of topical therapy in 66 patients with PG supports benefit of topical corticosteroid treatment [21]. Most patients (74 percent) received clobetasol propionate 0.05%; the remaining patients received topical tacrolimus 0.03 or 0.1% ointment. At six months, 28 of the 64 patients (44 percent) for whom information on healing was available had healed on topical therapy alone, including 20 of 47 (43 percent) treated with clobetasol and 5 of 10 (50 percent) treated with topical tacrolimus. The median time to healing was 145 days. Initial ulcer size was a significant predictor of time to healing. In a separate open-label study in which 5 of 13 patients treated with clobetasol 0.05% ointment or lotion achieved complete healing, the average time to healing was 6.5 weeks [22].

Although some clinicians, including ourselves, avoid intralesional injections due to concern for the induction of pathergy, case reports have documented efficacy of intralesional corticosteroid therapy in PG [10,23-26]. Concentrations of triamcinolone between 6 and 40 mg/mL have been utilized [27]. The corticosteroid is injected circumferentially into the ulcer periphery. (See "Intralesional corticosteroid injection".)

Cutaneous atrophy is one of the most common adverse effects of topical and intralesional corticosteroid therapy. Adverse effects are reviewed in greater detail separately. (See "Topical corticosteroids: Use and adverse effects", section on 'Adverse effects' and "Intralesional corticosteroid injection", section on 'Side effects, complications, and pitfalls'.)

Local calcineurin inhibitors — Topical tacrolimus in concentrations of 0.03% to 0.3% has demonstrated efficacy for PG in multiple case reports, a few prospective case series, and uncontrolled studies [20,21,28,29]. In one uncontrolled study, a compounded formulation of 0.3% tacrolimus in a carmellose sodium paste appeared to be effective for peristomal PG; 7 of 11 patients treated with the tacrolimus formulation and 5 of 13 patients treated with clobetasol 0.05% lotion or ointment achieved complete healing [22].

Topical tacrolimus is commercially available as a 0.03% and 0.1% ointment. We typically instruct the patient to apply the 0.1% ointment once to twice daily. Improvement may be evident within the first few days to weeks of treatment. However, complete healing of an ulcer may take several weeks to a few months [29-31]. Treatment is usually well tolerated; occasionally, patients experience mild burning sensations at the site of application [30].

Other calcineurin inhibitors may have benefit for PG, but fewer data are available on these agents. A case report documented improvement with pimecrolimus 1% cream [32]. Improvement with topical or intralesional cyclosporine has been described in a few patients [33-36].

More extensive or rapidly progressing disease — Most patients with PG cannot be managed with local therapy alone. Systemic treatment is used as a first-line intervention in PG that is not limited to a few superficial ulcers or a solitary plaque of vegetative PG. Systemic agents are also appropriate for patients with mild PG that fails to improve with local therapy.

The systemic therapies utilized in PG are immunosuppressive and immunomodulatory agents that calm the inflammatory process to allow for wound healing. Systemic glucocorticoids often induce a rapid response and are typically used as initial therapy [3]. In patients who cannot tolerate or fail to respond to systemic glucocorticoids, treatment with systemic cyclosporine can be attempted. Of note, topical or intralesional corticosteroids and topical tacrolimus are often used as adjuncts to systemic therapy. (See 'Local corticosteroids' above and 'Local calcineurin inhibitors' above.)

Systemic glucocorticoids — Multiple case reports, case series, and our clinical experience support the use of systemic glucocorticoids for the treatment of PG [10,37]. The response of PG to systemic glucocorticoid varies, as demonstrated in a single-blind randomized trial (n = 112) that found a similar pace of improvement among patients assigned to prednisolone (initial dose 0.75 mg/kg per day) and patients assigned to cyclosporine (initial dose 4 mg/kg per day) over the first six weeks of treatment, but only a 47 percent rate of complete healing in both groups after six months of treatment [38]. Placebo-controlled randomized trials assessing efficacy of systemic glucocorticoids are lacking.

We typically initiate treatment with 0.5 to 1.5 mg/kg per day of oral prednisone or its equivalent, with a maximum dose of 60 mg of prednisone per day. In very aggressive or painful disease, intravenous pulse corticosteroids (1 g methylprednisolone per day for one to five days) can be used as initial therapy [39-41].

The response to systemic glucocorticoids is usually rapid; stabilization of the disease is often evident within the first week [42]. Pain also tends to improve soon after the initiation of treatment. However, since complete ulcer healing may take weeks to months, and long-term therapy with systemic glucocorticoids is associated with significant adverse effects, glucocorticoids are tapered as soon as is feasible. We typically begin to taper glucocorticoids once disease progression has stopped and clear signs of improvement are noted (reductions in pain, visible inflammation, and wound size).

We aim to taper and discontinue glucocorticoids within 4 to 10 weeks and monitor patients closely for continued improvement. We usually add a glucocorticoid-sparing agent (such as mycophenolate mofetil, cyclosporine, azathioprine, or infliximab) to maintain improvement during and after tapering. Tapering glucocorticoids too rapidly may precipitate disease flares [42].

Systemic cyclosporine — Cyclosporine is used as an alternative first-line agent in patients who cannot tolerate glucocorticoid therapy and as an adjunctive or alternative therapy for patients who fail to respond adequately to glucocorticoids [10]. A single-blind randomized trial that compared cyclosporine with prednisolone, several retrospective analyses, and multiple case reports support a beneficial effect of cyclosporine therapy in some patients [23,37,38,43-46]. As with systemic glucocorticoids, placebo-controlled randomized trials evaluating the efficacy of cyclosporine are lacking. (See 'Systemic glucocorticoids' above.)

We typically initiate treatment at a dose of 4 to 5 mg/kg and subsequently taper as tolerated [11]. Cyclosporine therapy can lead to unfavorable side effects, such as renal toxicity and hypertension. Limiting cyclosporine treatment to less than one year is suggested [3]. (See "Pharmacology of cyclosporine and tacrolimus", section on 'Side effects'.)

SECOND-LINE AND ADJUNCTIVE THERAPIES — In addition to the treatments described above, a variety of other systemic therapies appear to have value for the treatment of pyoderma gangrenosum (PG). Comparative studies of the efficacies of systemic treatments for PG are lacking.

Documentation of successful treatment with anti-TNF biologic agents is increasing, and although mycophenolate mofetil, azathioprine, and methotrexate often are not adequate as monotherapy, they may be beneficial when used in conjunction with systemic glucocorticoids or other systemic therapies [3,27]. Dapsone and minocycline also appear to be useful in some patients with PG, and we often attempt to treat patients with mild PG with these generally well-tolerated agents prior to utilizing more aggressive immunosuppressive therapies [3].

Infliximab — The use of infliximab, a chimeric antibody against tumor necrosis factor (TNF)-alpha, in PG is supported by a placebo-controlled randomized trial of 30 adults with PG, many of whom were concomitantly treated with topical or systemic therapy (primarily oral prednisolone) [47]. At the start of the trial, patients were given either a single 5 mg/kg infusion of infliximab (n = 13) or placebo (n = 17). After two weeks, significantly more patients in the infliximab group had clinical signs of improvement (46 versus 6 percent).

Patients in both groups who did not exhibit improvement at week two were then given open label infliximab (5 mg/kg single dose). At week six, 20 of the 29 patients who received infliximab (69 percent) had improved, and 6 patients achieved complete remission (21 percent). There was no significant difference in the response to treatment among patients with (n = 18) and without (n = 11) inflammatory bowel disease. Long-term follow-up was not performed.

In addition to the randomized trial, other studies have documented efficacy of infliximab [48,49]. As an example, a multicenter retrospective study of 13 patients with refractory PG and inflammatory bowel disease treated with 5 mg/kg of infliximab (1 to 24 infusions over zero to four years and in conjunction with other systemic therapies) found that all 13 patients achieved complete healing. The mean times to initial response and complete healing were 11 days (range 2 to 30 days) and 86 days (range 7 to 210 days), respectively [49]. Ten patients required periodic infusions every 4 to 12 weeks to maintain the clinical response. All patients who were taking systemic glucocorticoids were able to discontinue glucocorticoid therapy.

The treatment regimens for infliximab and the time to response to infliximab vary considerably across case reports and studies [50]. The optimal treatment regimen is yet to be determined. We typically administer 5 mg/kg of infliximab at weeks zero, two, and six, followed by infusions every six to eight weeks [11]. Given the efficacy of infliximab in Crohn's disease, infliximab may be particularly useful in the population of patients with PG who also suffer from refractory Crohn's disease. (See "Treatment of Crohn disease in adults: Dosing and monitoring of tumor necrosis factor-alpha inhibitors".)

Potential adverse effects of infliximab include infusion reactions, infections, demyelinating disease, and heart failure. The side effects of TNF-alpha inhibitors are discussed in greater detail separately. (See "Tumor necrosis factor-alpha inhibitors: An overview of adverse effects".)

The requirement for infusion and the high cost of the drug make infliximab treatment less favorable for some patients.

Other biologic TNF-alpha inhibitors — In addition to infliximab, other biologic TNF-alpha inhibitors may be beneficial in PG. Adalimumab (40 mg weekly, 40 mg twice monthly, and other regimens) has been associated with ulcer healing in case reports [51-54]. Most of the published cases have involved patients with concomitant inflammatory bowel disease or rheumatoid arthritis. Improvement in PG with etanercept (25 to 50 mg twice weekly) has also been reported in a small retrospective series and case report [55,56]. However, in our experience, adalimumab seems to be more efficacious.

In theory, other biologic TNF-alpha inhibitors might be useful for PG, particularly in patients with PG-associated diseases that are treated with these agents. The efficacy of drugs such as certolizumab pegol (utilized for Crohn's disease) and golimumab (utilized for rheumatoid arthritis) in PG remains to be determined.

Conventional immunosuppressants — Immunosuppressive agents such as mycophenolate mofetil, methotrexate, and azathioprine have been utilized for the treatment of PG. The onset of action of these drugs is slower than for systemic glucocorticoids and cyclosporine. These agents are generally considered to be most beneficial when used as adjunctive or glucocorticoid-sparing agents, rather than as monotherapy [3].

Multiple cases of improvement in PG with mycophenolate mofetil have been reported [17,23,44,57-61]. Mycophenolate mofetil appeared beneficial in a retrospective study of 26 patients with PG treated with mycophenolate mofetil and prednisolone (with or without other immunomodulatory agents) for at least one month [61]. Improvement in disease severity during treatment was noted in 22 patients (85 percent). Moreover, in a retrospective study of seven patients treated with mycophenolate mofetil for at least two months, four of seven had complete healing, including two patients for whom mycophenolate mofetil was the only systemic therapy given for PG [60]. The use of methotrexate [62] and azathioprine [43,63] as adjuncts to other immunosuppressive therapies is supported by reports of individual patients [64].

Typical doses utilized for these agents are as follows: mycophenolate mofetil (2 to 3 g per day), methotrexate (10 to 30 mg per week), and azathioprine (100 to 300 mg per day) [11]. Adverse effects of these agents are reviewed separately. (See "Mycophenolate: Overview of use and adverse effects in the treatment of rheumatic diseases" and "Major side effects of low-dose methotrexate" and "Pharmacology and side effects of azathioprine when used in rheumatic diseases", section on 'Adverse effects'.)

Dapsone — In case reports and small series, dapsone has been associated with improvements in PG when administered as monotherapy or as a glucocorticoid-sparing agent [23,37,43,44,65-69]. Dapsone is usually prescribed in doses of 50 to 200 mg per day [11].

As noted above, we often attempt treatment with dapsone prior to more aggressive immunosuppressive therapies in patients with mild disease because of the generally well-tolerated nature of this agent. However, dapsone therapy should be avoided in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to an elevated risk for drug-induced hemolytic anemia in this population. We obtain a G6PD level prior to drug initiation. (See "Diagnosis and management of glucose-6-phosphate dehydrogenase (G6PD) deficiency", section on 'Inciting drugs, chemicals, foods, illnesses' and "Diagnosis and management of glucose-6-phosphate dehydrogenase (G6PD) deficiency", section on 'Screening tests'.)

Minocycline — Minocycline has been linked to improvement in patients with PG when used as monotherapy or a glucocorticoid-sparing agent [37,70-79]. Adult patients can be treated with 100 mg twice daily. Similar to other tetracyclines, minocycline should not be administered to children under the age of nine years due to adverse effects on tooth development.

REFRACTORY DISEASE — Intravenous immune globulin (IVIG) and the alkylating agents cyclophosphamide and chlorambucil are options for patients with severe pyoderma gangrenosum (PG) that is refractory to first- and second-line agents. The high cost of IVIG and the requirement for intravenous infusion limits its routine use. The potential for severe adverse effects limits the use of alkylating agents.

Intravenous immune globulin — IVIG is typically given in divided doses over the course of two to five days, repeated monthly. Efficacy data for IVIG for PG are limited. A systematic review of cases and case series documenting treatment of refractory PG with IVIG (often in conjunction with systemic glucocorticoids) found complete responses in 26 of 49 patients (53 percent) and complete or partial responses in 43 of 49 patients (88 percent) [80]. The mean time to initial response was 3.5 weeks, and patients were treated for an average of 5.9 months. Limitations of the review included potential publication bias given that most data were derived from case reports and a paucity of long-term, follow-up data in the included patients. Moreover, failures to respond to retreatment with IVIG upon disease relapse have occurred. Well-designed prospective trials are necessary to clarify the efficacy of IVIG for PG. (See "Overview of intravenous immune globulin (IVIG) therapy".)

Alkylating agents — Although a few case reports and uncontrolled studies document improvement in refractory PG with pulsed intravenous cyclophosphamide [81-83] or chlorambucil [84-86], concern for myelosuppression and other severe adverse effects limits the use of these therapies. In an uncontrolled study of nine patients with PG treated with monthly infusions of cyclophosphamide (500 mg/m² for up to six treatments), seven patients achieved complete remission, one achieved partial remission, and one failed to respond to therapy [81]. Four patients achieved complete healing prior to the third treatment. Two patients relapsed within three months after the cessation of therapy.

Chlorambucil appeared to be effective for recalcitrant PG in an uncontrolled study of six patients who were treated with chlorambucil (2 to 4 mg per day) with or without prednisone therapy [84]. Improvement was noted in six to eight weeks, and healing of ulcers occurred within 2 to 10 months in all patients. All patients who were also receiving prednisone for PG were able to discontinue prednisone therapy. Prolonged remissions (four to nine years) were sustained in four patients who discontinued chlorambucil after 6 to 24 months of therapy.

OTHER THERAPIES — Multiple other interventions have been reported to be effective in individual patients. Examples of topical agents include sodium cromoglycate [23,87,88], nicotine [89-91], benzoyl peroxide [92,93], 5-aminosalicylic acid [94], nitrogen mustard [95], and platelet-derived growth factor [96,97]. Additional systemic agents that may be beneficial to patients include clofazimine [43,98], colchicine [99,100], doxycycline [37], interferon alfa [101], melphalan [102], mercaptopurine [103], metronidazole [104], potassium iodide [105], sulfasalazine [44], tacrolimus [106], thalidomide [37,107,108], ustekinumab [109,110], canakinumab [111], tofacitinib [112], and secukinumab [113]. Apheresis of leukocytes [114-118] and plasmapheresis [83] have also been used for treatment.

CESSATION OF THERAPY — Once complete healing of lesions has occurred, treatment cessation can be attempted. Therapy should be gradually tapered and stopped over the course of several months rather than abruptly discontinued.

Prolonged treatment is necessary for some patients. In a series of 42 patients with pyoderma gangrenosum (PG) who were followed for a median of 26.5 months, 56 percent of the 34 patients who remained alive during the follow-up period required continuing pharmacologic therapy, and 44 percent were able to maintain complete remission without therapy [43].

PAIN MANAGEMENT — Ulcers of pyoderma gangrenosum (PG) are often associated with significant pain that appears out of proportion to the clinical appearance of lesions. Although pain may improve during treatment, some patients require the use of narcotic agents to manage discomfort. Consultation with a pain management specialist may be beneficial [4].

PROGNOSIS — Follow-up studies of patients with pyoderma gangrenosum (PG) suggest that with treatment, more than 50 percent of patients achieve complete wound healing within one year:

●In an Australian series of 26 patients hospitalized for PG, 6 of 12 patients available for follow-up six months after hospital discharge had complete ulcer healing [119].

●In a series with 64 patients with classic PG and 22 patients with bullous (atypical) PG, the mean time to complete remission (wound healing and absence of active disease) was 11.5±11.1 months in patients with classic PG and 9±13.7 months in patients with bullous PG [1]. Overall, 68 percent of patients achieved complete remission within six months, and 95 percent were in remission within three years.

The effect of treatment of associated underlying medical disorders on disease activity in patients with PG is variable, as the course of PG does not always parallel that of the related underlying disease [23]. Improvement in PG has been reported in some patients following proctocolectomy for inflammatory bowel disease [120]. However, PG may also occur peristomally or in other locations following proctocolectomy [23,121-125].

PG typically heals with scars, which can be disfiguring. New lesions may develop during or after healing of other lesions. Relapses can appear after long periods of disease quiescence [126].

Death may occur due to underlying associated disorders, particularly in patients with hematologic disease, or to complications directly related to ulcers (eg, sepsis) [43,127]. Due to the association between bullous PG and hematologic disease, patients with bullous PG who present without an identifiable underlying hematologic disorder should be followed closely [11].

PREVENTION — There are no specific measures that have been shown to prevent the initial development of pyoderma gangrenosum (PG). In patients with an existing diagnosis, avoidance of trauma may help to reduce the development of new lesions. If patients with pyoderma gangrenosum require surgery for other indications, wound closure with subcuticular stitches and close postoperative follow-up with a dermatologist is suggested.

Some authors have suggested that administering systemic glucocorticoids during and for two weeks or more after surgery may help to prevent the development of new lesions in patients with aggressive PG [2]. However, the impact of this intervention has not been formally studied.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Pyoderma gangrenosum".)

INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Pyoderma gangrenosum (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Pyoderma gangrenosum (PG) is an uncommon inflammatory and ulcerative disorder that may occur independently or in association with a variety of systemic diseases. (See 'Introduction' above.)

●Data on treatments for PG are limited and definitive guidelines for patient management are lacking. Treatment typically involves the use of one or more topical or systemic immunomodulatory agents. (See 'Approach to treatment' above.)

●Wound care measures in PG are intended to optimize the environment for wound healing. Wound dressings that maintain a moist wound environment are preferred. Due to the potential for pathergy (exacerbation of PG at sites of tissue injury), unnecessary trauma should be avoided. (See 'Wound management' above.)

●The role of surgery is controversial in PG due to the possibility of the induction of pathergy. Surgical procedures should be avoided in most cases. Surgery may be necessary in select cases, such as those in which tissue necrosis presents a risk for infection or in which exposure of vital tissues such as tendons or ligaments is present. (See 'Surgery' above.)

●The severity of PG influences the approach to treatment. For patients with mild, localized PG (few superficial ulcers or a plaque of vegetative PG), we suggest initial treatment with a high potency or superpotent topical corticosteroid or topical tacrolimus (Grade 2C). Patients with mild PG who fail to improve with local interventions should be treated with systemic therapy. We often attempt treatment with dapsone or minocycline prior to the initiation of more aggressive immunomodulatory therapies. (See 'Limited disease' above.)

●For patients with more extensive or rapidly progressing PG, systemic treatment is indicated. We suggest initiating treatment with systemic glucocorticoids (Grade 2C). Cyclosporine with or without systemic glucocorticoids may be used as an alternative first-line therapy. (See 'More extensive or rapidly progressing disease' above.)

●A wide variety of other systemic immunomodulatory agents appear to have efficacy in PG. Infliximab was effective for PG in a randomized trial, and may be particularly useful in patients who require treatment of both PG and Crohn's disease. The cost of infliximab and the requirement for infusion are potential limiting factors for the use of infliximab therapy. (See 'Second-line and adjunctive therapies' above.)

●It is estimated that with treatment, more than half of patients with PG achieve wound healing within one year, and almost all patients achieve remission with longer follow-up. However, relapses can occur after long periods of disease remission. (See 'Prognosis' above.)