[Erosive pustular dermatosis of the legs: retrospective study of 16 cases]

Erosive pustular dermatosis of the leg (EPDL) is a chronic clinical entity comprising combined erosion, pustules and crusts on the legs. There is still some discussion of the independent existence of this condition in the absence of specific diagnostic criteria. The purpose of this study is to describe the clinical and laboratory characteristics of EPDL based on a series of patients presenting a clinical picture consistent with this diagnosis.

This retrospective study included all patients seen in our department between 2005 and 2009 presenting a clinical picture consistent with EPDL, in accordance with the initial description. We collated and carried out descriptive analysis of the clinical features and progression of the disease and of laboratory results (microbiology, immunology and vascular tests).

In all of the 16 patients included (mean age: 81 years; sex ratio M/F: 0.2), lesions were consistently located in the middle third of the anterior aspect of the leg and associated with ochre dermatitis and skin atrophy; they were bilateral in 10 of the 16 patients. For the most part, laboratory tests were negative or inconclusive, with the exception of direct cutaneous immunofluorescence (DIF). DIF was performed in 14 patients and in three cases showed linear C3 deposits, thus confirming the diagnosis of pretibial bullous pemphigoid. In the 13 remaining cases, a diagnosis of idiopathic EPDL was made. Three of these 13 patients were either presenting or had previously presented squamous cell carcinoma of the leg. Topical corticosteroids were effective in 12 of these 13 cases (mean treatment duration: six months). Relapse was common (6/12).

Our study demonstrates the need for skin biopsy with DIF for patients presenting a clinical picture evocative of EPDL, since the clinical presentation can be very similar to that of pretibial pemphigoid. Trophic disorders associated with venous stasis are common in EPDL, although they are difficult to interpret because of the high prevalence of this condition among the elderly. Mention must be made of associated marked sun damage, suggesting a possible relationship between EPDL and erosive pustular dermatosis of the scalp.