Asparagus-induced fixed food eruptions mimicking cutaneous lupus.

Recurrent localised inflammatory skin reactions healing with hyperpigmentation can be induced by certain drugs and are known as fixed drug eruptions. In few cases also food was described to induce these symptoms, and the term " fixed food eruptions " was coined. Fixed food eruptions are rare, the first case was reported in 1992 (1) and the term in analogy to the clinical similarities to fixed drug eruptions was coined in 1996 (2). Since then few cases with different causes were described: cheese crisps, strawberries, lentils, lactose, quinine, cashew nuts and Japanese sand lance (3). We report the second case in which asparagus caused fixed food eruptions (4). Our patient was initially diagnosed as cutaneous lupus based on clinical appearance of the skin lesions, their development in sun-exposed areas, their seasonal manifestation and histopathology. However, asparagus was identified as the causative agent by skin testing and oral provocation. Fixed food eruptions are rare but should be included in the differential diagnosis when considering the origin of recurrent and persistent erythematous skin lesions. A 69-year-old woman presented with a two-year history of persistent, non-pruritic inflammatory skin lesions in sun-exposed areas: face, décolleté and shoulders. Erythematous skin lesions developed in spring. These symptoms disappeared after weeks, leaving behind hyperpigmentation that resolved during the next winter. The erythematous lesions were round to annular, sharply marginated and infiltrated. Together with the histopathology revealing focal interface dermatitis with some dermal deposition of mucin (Fig. 1), initially the diagnosis of cutaneous lupus erythematosus was made and lupus erythemato-sus tumidus and subacute cutaneous lupus were considered. However, autoantibodies specific for nuclear antigens were negative and no deposition of autoantibodies in the tissue as studied by direct immunofluorescence was found. The detection of anti-thyreoglobulin antibodies were in accord with the patient's previous diagnosis ofHashimotòs disease. The skin lesions faded slowly after several weeks of topical treatment with topical glucocorticoid prednicarbate, leaving areas with hyperpigmentation (Fig. 2a). The following year the patient reported a recurrence of the skin lesions after consuming meals of cooked asparagus (Asparagus officinalis). Prick-and patch-testing with raw and cooked asparagus in uninvolved and previously affected skin lesions were negative. An intradermal testing at a non-involved skin site with a water soluble asparagus protein extract (1:500) turned positive after 6 h and was negative in a healthy control. Lymphocyte transformation test (LTT) with titrated doses of asparagus protein remained unreactive. No asparagus-specific IgG was detectable by …