Compositae dermatitis in a Danish dermatology department in 1 year (II). Clinical features in patients with Compositae contact allergy.

During our first year of routine testing with Compositae allergens and extracts, contact allergy to Compositae was frequently found in eczema patients (4.5%), especially in middle-aged or elderly persons. Based on clinical patterns, patch test reactions and the long-term course of the disease, 4 groups of patients were recognized: (a) a small group with localized eczema; (b) another with classic Compositae dermatitis of exposed skin; (c) a 3rd group, the largest, with localized eczema that suddenly one summer turned into a widespread dermatitis; (d) a 4th group with a vesicular hand eczema and more-or-less widespread dermatitis with seasonal variation from the beginning. 65% of the patients had vesicular hand eczema at some time, partly reflecting the frequency of atopy (25%) and metal allergy (44%). 75% of the patients had contact allergy to > or = 1 compounds besides Compositae. Thus, Compositae allergy may be primary, e.g., in young patients with occupational plant contact, or secondary to other contact allergies, perhaps as a result of increased individual susceptibility. The clinical patterns in the latter patients were most often a widespread dermatitis with summer exacerbation. The variability in the clinical picture makes routine patch testing with Compositae allergens recommendable.