[Plantar hidradenitis].

INTRODUCTION

Plantar hidradenitis, one of several possible causes of painful papulo-nodular lesions of the foot in children and young adults, was recently described as the presence of characteristic lesions of the eccrine sweat glands.

CASE REPORT: A 15-year-old boy consulted for a sudden-onset painful eruption on the sole of the right foot. Physical examination revealed papulo-nodular erythromato-violet infiltrated lesions located on the anterior part of the right planta. Histology examination showed dense neutrophil inflammatory infiltration predominating at the dermo-hypodermic junction around the eccrine sweat glands. The excretory ducts of the sweat glands were infiltrated but the secretory glomerulae were intact. A dense infiltration of venular thrombi without vasculitis was also seen. The lesion regressed with aspirin (8 days) and rest. No recurrence has been recorded after 18 months.

DISCUSSION: This clinical and histological presentation led to the diagnosis of plantar hidradenitis, confirming the disease entity. Former cases may have been described as trauma-induced plantar urticaria or plantar erythema nodosum. This diagnosis should be entertained in children or young adults with painful papulo-nodular eruptions of the soles. The histology examination should include the eccrine sweat glands.