[Neutrophilic dermatosis of the hands]

In 1964, based on eight cases, R. Sweet described a form of "acute febrile neutrophilic dermatosis" that was quickly renamed Sweet's syndrome. Over time, other entities (pyoderma gangrenosum, erythema elevatum diutinum, etc.) came to be included in the same nosological group, giving rise to the concept of neutrophilic dermatosis. In addition to types of passage between these different diseases, neutrophilic dermatoses may have a variety of atypical presentations such as that described as "neutrophilic dermatosis of the hands", of which we present a case herein.

A 60-year-old woman with non-insulin-dependent diabetes and mild psoriasis was consulting for an eruption mainly on the hands. The lesions, of various shapes, comprised pustules and large bullous lesions on purple oedematous skin; these were painful and some were progressing to ulceration. They measured between 0.5 and 3 cm and were filled with an opaque liquid. These lesions were painful and some were progressing towards ulceration. The patient was also presenting inflammatory joint pain. The histopathology study revealed infiltration of the dermis, predominantly by neutrophils. A diagnosis of neutrophilic dermatosis was made without any clearly discernible distinction between Sweet's syndrome, palmoplantar pustulosis or pyoderma gangrenosum.

Since the initial description of Sweet's syndrome in 1964, many unusual cases have been described in the literature (associated with neoplasias or systemic diseases, concomitant pustular or bullous lesions, etc.). In 1995, Strutton et al. described a new entity, pustular vasculitis of the hands, based on six cases, which is fairly similar to the present case. Understanding of this syndrome developed and Gallaria renamed it neutrophilic dermatosis of the dorsal hands. Walling and Duquia termed this form of dermatosis palmoplantar Sweet syndrome.

This case highlights the difficulties in clearly distinguishing forms of neutrophilic dermatosis, adding to the notion of a continuum in neutrophilic disease.