Overview

Pyoderma gangrenosum (PG) is a rare (incidence in USA is 1 in 100,000) ulcerating skin disease that may affect any part of the body, but is most common below the knees with preference for the pretibial area. The ulcerative lesions are painful, exhibit sudden onset and rapid progression, and consist of a deep necrotic region up to 4 inches in diameter surrounded by a purple to red pustular base. A common pathognomonic feature is for the margin to be undermined [Wolllina2007] [Habif2004] [MedScape-Pyoderma] [DermNetNZ-Pyoderma] [Merck-Pyoderma] [Wiki-Pyoderma]

The lesions usually show an infiltration of neutrophils suggestive of an immune response to a local infectious agent, but no causative agent has been identified [Habif2004] [MedScape-Pyoderma] In some cases neutrophils are not present [DermNetNZ-Pyoderma]

PG was first described by dermatologists at Mayo Clinic in 1930 [Mayo-Pyoderma]

In about half of all cases, PG is associated with some other underlying inflammatory condition or malignancy such as:

However no cause-effect linkage has been established for any of the above, and the remaining half of PG cases have no other apparent associations. Note however, that some of the above disorders are also in the differential diagnoses listed below.

PG lesions can also occur in other organ systems, such as:

Culture-negative pulmonary infiltrates are the most common extracutaneous manifestation [MedScape-Pyoderma]

Pathergy is common in cases of PG - new lesions develop at sites of trauma (similar to the Koebner (Köbner) phenomenon seen in psoriasis) [Merck-Pyoderma]

Links to photos of pyoderma gangrenosum:

Please see conventional, complimentary and alternative medical treatments for important background information regarding the different types of medical treatments discussed on this page. Naturopathic, Complimentary and Alternative treatments that may be considered include:

Etiology

Since no infectious agent has been isolated from the ulcerating lesions, many researchers speculate that pyoderma gangrenosum is some sort of autoimmune process.

Diagnosis

The diagnosis of pyoderma gangrenosum is by exclusion of other possible disease processes (see differential diagnosis below).

Typical workup:

It is important to remember that PG is a diagnosis of exclusion, and is often incorrectly diagnosed. In one study, out of 240 cases diagnosed and treated for PG, it was found that 95 patients actually had some other disorder. Of the cases that were misdiagnosed, while some improved with treatment directed at PG, most either did not respond or were actually made worse [Weenig2002].

Differential Diagnosis

The differential diagnosis of PG may be broken down into six disease categories as follows [Wolllina2007]:
  1. Vascular occlusive or venous disease (biopsy) [Weenig2002]
  2. Vasculitis (biopsy) [Weenig2002].
  3. Cancer/Malignancy (biopsy) [Weenig2002].
    • Lymphoma cutis [Weenig2002]
    • Leukemia cutis [Weenig2002]
    • DermIS - Basal Cell Carcinoma
      DermIS - Basal Cell Carcinoma
    • DermIS - Ulcus Terebrans
      DermIS - Ulcus Terebrans
    • DermIS - Squamous Cell Carcinoma
      DermIS - Squamous Cell Carcinoma
    • Langerhans-cell histiocytosis [Weenig2002]
    • DermIS - Ulcus Terebrans
      DermIS - Ulcus Terebrans
  4. Infectious Disease (biopsy, culture) [Weenig2002].
  5. Exogenous tissue injury (biopsy) [Weenig2002].
    • DermIS - Progressive Post-operative Gangrene
      DermIS - Progressive Post-operative Gangrene
    • DermIS - Hidradenitis Suppurativa
      DermIS - Hidradenitis Suppurativa
    • Insect or spider bites [Wolllina2007]
    • Factitious panniculitis/dermatitis, Münchhausen syndrome Go to DermISDermIS [Wolllina2007], [Weenig2002]&>
  6. Drug reactions (history, biopsy) [Weenig2002].
  7. Other/Uncategorized

Treatment

Conventional Treatment

The standard allopathic treatment is similar to other autoimmune diseases. The first line treatment consists of immune suppression using topical, locally injected, or systemic corticosteroids.

Small lesions may be treated with:

Larger lesions require more aggressive immunosuppression. Oral corticosteroids (e.g. prednisone/Deltasone 60 to 80mg PO once/day) may be required for several months in high dose [DermNetNZ-Pyoderma] [Merck-Pyoderma] supplemented if necessary by drugs such as the following:

Surgical procedures are rarely used because they can aggravate the condition [Mayo-Pyoderma]

Antibiotics such as flucloxacillin are often prescribed as a precaution to prevent secondary infections, or in case the surrounding tissues exhibit cellulitis [Mayo-Pyoderma] [DermNetNZ-Pyoderma]

In some cases, protection of the skin from trauma may prevent a recurrence [Mayo-Pyoderma]

PG is a painful disease that may require the use of narcotics [MedScape-Pyoderma]

Naturopathic, Complimentary and Alternative Treatments

Low Dose Naltrexone (LDN)

According to the Low Dose Naltrexone home page [LDN], LDN has been seen to benefit many different autoimmune diseases. Although Dr. Weyrich is not aware of any reports of treating pyoderma gangrenosum using LDN, Dr. Weyrich speculates that pyoderma gangrenosum may also respond to LDN.

Dr. Weyrich has been trained in the use of Low Dose Naltrexone (LDN). However, Dr. Weyrich has not treated any cases of pyoderma gangrenosum with LDN.

Please see What is Low Dose Naltrexone? for more information.

Sequelae

Pyoderma gangrenosum often appears at the site of some minor physical trauma or folliculitis. This may lead to abscess formation or leukocytoclastic vasculitis. The lesions then evolve to suppurative granulomatous dermatitis.

The prognosis of pyoderma gangrenosum is generally good. PG may regress spontaneously or with treatment, leaving prominent fibroplasia (scarring) [Hurwitz1993] [Mayo-Pyoderma] [Habif2004] [MedScape-Pyoderma]

Perhaps the greatest danger with PG is misdiagnosis of infectious or malignant diseases as PG, and consequent inappropriate treatment for PG which may delay proper treatment or even be counterproductive. A review of the charts of 240 patients with a diagnosis of pyoderma gangrenosum found that, out of those misdiagnosed as PG and treated accordingly, "five patients died from overwhelming infection, and four died from progression of disease" [Weenig2002].

The disease reoccurs in about 30% of all cases [Habif2004].

Pathophysiology

The mechanism of pyoderma gangrenosum is poorly understood, but dysregulation of the immune system is believed to be involved [MedScape-Pyoderma] [Weenig2002]. Specifically, neutrophil dysfunction (defects in chemotaxis or hyperreactivity) [Adachi1988], overexpression of interleukin-8 (IL-8) [Oka2000] and overexpression of interleukin-16 (IL-16) [Lindor1997], [Yeon2000].

Hypotheses

A possible causal linkage between pyoderma gangrenosum and inflammatory bowel disease is suggested by the observation made by Mayo Clinic that some PG patients with ulcerative colitis respond to total colectomy (removal of the colon) [Mayo-Pyoderma]

ICD-9 Codes

ICD-9 CodeDescriptionComments
686.01  

References