Weenig et al listed a number of conditions that may mimic pyoderma gangrenosum (PG). Failure to consider these in the differential diagnosis can result in misdiagnosis. The authors are from the Mayo Clinic in Rochester.


Conditions (other than PG) that can cause cutaneous ulcers include:

(1) vasculitis

(2) vascular occlusions

(3) skin involvement in hematologic malignancies

(4) skin infection

(5) drug-induced skin ulcers

(6) toxin-induced skin ulcers

(7) other


Causes of vasculitis:

(1) Wegener's granulomatosis

(2) polyarteritis nodosa (PAN)

(3) cryoglobulinemia (as vasculitis or occlusive)

(4) Takayasu's vascultiis

(5) leukocytoclastic vasculitis

(6) drug-induced lupus


Conditions with vascular occlusions:

(1) antiphospholipid antibody

(2) livedoid vasculopathy

(3) venous stasis ulceration

(4) small vessel occlusive arterial disease

(5) Klippel-Trenaunay-Weber syndrome


Hematologic malignancies:

(1) T cell lymphoma (angiocentric, anaplastic large cell, Mycosis fungoides)

(2) leukemia cutis

(3) Langerhans cell histiocytosis


Skin infection:

(1) fungal infection

(2) herpes simplex virus

(3) mycobacterial infection

(4) amebiasis cutis

(5) Pseudomonas aeruginosa or other Gram negative bacteremia


Drug-induced skin ulcers:

(1) hydroxyurea


Toxin-induced skin ulcers:

(1) bromoderma

(2) spider bites (brown recluse spider)



(1) ulcerating necrobiosis lipoidica

(2) cutaneous Crohn's disease

(3) Munchausen's syndrome or other factitious disorder

(4) injection site reaction

(5) contact vulvitis


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