INTROUCTION
Pyoderma gangrenosum (PG) is a rare non-infectious neutrophilic
dermatosis of unknown etiology, characterized clinically by chronic and
recurrent cutaneous ulcers with a necrolytic border and is commonly
associated with underlying systemic disease. About 33-50% of the
patients are known to have various underlying diseases such as
inflammatory bowel disease (IBD), hematological malignancies and
rheumatoid arthritis.1,2 Whereas palmoplantar
pustulosis (PPP) presents with erythematous and scaly plaques studded
with sterile pustules localized on the palms and/or soles and has a
chronic and relapsing course. It is commonly associated with psoriasis
vulgaris and or psoriatic arthritis.3
Although the pathogenesis of PG and PPP is poorly understood, recent
studies have suggested that dysregulation of the innate immunity
involving several common cytokines such as tumor necrosis factor-a
(TNF-α), interleukin (IL)-17 and (IL)-23 may play important role in the
development of both PG and PPP and share a common characteristic
histological feature of neutrophilic infiltration in
skin.4,5,6 Psoriasis and psoriatic arthritis have been
found to be associated in up to 10% of PG patients7but the coexistence of PG and PPP in the same patient has been reported
only in 5 cases in the literature till date8,9,10 and
all were reported from Japan. We report herein a female patient
with PPP who developed PG on her lower leg as a first case report other
than in Japanese population and tried to justify the coexistence of both
the conditions based on the review of the literature.