[An atypical form of Kimura's disease].

BACKGROUND: Kimura's disease is a rare benign chronic inflammatory disease of unknown aetiology.

CASE REPORT: An 18-year-old atopic Brazilian patient consulted for recurrent facial eczema that improved slightly under topical corticosteroids. He presented a large infiltrated and eczematous subcutaneous plaque on the right supraorbital area, together with eyelid oedema. This was associated with complete right eyebrow alopecia, oedema of the upper lip and infiltrated facial papules. The tests showed hypereosinophilia (4000/mm(3)), a high IgE level (3786 kIU/L) and proteinuria (0.3g/24h). Histological examination revealed a lymphocytic eosinophil-rich inflammatory infiltrate in the superficial and deep dermis, with some lymphoid follicles in depth and proliferation of post-capillary venules. All of these elements led to the diagnosis of Kimura's disease.

DISCUSSION: We report an unusual clinical form of Kimura's disease in a Brazilian patient. This disease has been classically described in young Asian men. In our case, a particularly large infiltrated and oedematous subcutaneous plaque was noted. In fact, the more common forms appear as subcutaneous nodules on the head and neck, which may be associated with locoregional adenopathy, involvement of the salivary glands, hypereosinophilia and raised serum IgE. In our case, the skin lesions, characterized by a large infiltrated and oedematous subcutaneous plaque, were unusual and could evoke IgG4-related disease.

CONCLUSION: We report a case of Kimura's disease with an atypical presentation. The diagnosis was established by comparing certain histopathological features, and the possibility of IgG4-related disease was discussed.