Contact and photocontact sensitization in chronic actinic dermatitis: sesquiterpene lactone mix is an important allergen

Abstract

Summary Eighty‐nine patients with chronic actinic dermatitis (CAD) were retrospectively studied: 69 (78%) male and 20 (22%) female, with mean ages of 66 and 64 years, respectively; nine (10%) were dark skinned. Eight (9%) were abnormally sensitive to UVB wavelengths alone, 74 (83%) to UVB and UVA, and seven (8%) to UVB, UVA and visible radiation. Eighty‐six patients were patch tested to an extended standard European series of contact allergens, including in 80 cases a 0.1% mix of three sesquiterpene lactones, and photopatch tested to a standard photopatch series. Sixty‐four of these 86 patients (74%) had positive patch or photopatch tests; 36% (29 of 80) were sensitive to the sesquiterpene lactone mix, 21% (18 of 86) to fragrance compounds, 20% (17 of 86) to colophony, and 14% (12 of 86) to rubber chemicals. Ten (12%) had positive photopatch tests; five (6%) to musk ambrette, six (7%) to sunscreens and one to both. Fourteen of the eighty‐nine patients with CAD (16%) had preceding endogenous eczema. In 18 of 86 patients (21%), CAD occurred alone, with neither detectable contact nor photocontact allergy, nor a preceding history of endogenous eczema. This study confirms the association between Compositae (sesquiterpene lactone) dermatitis and CAD.

Persistent Photosensitivity After Allergic Contact Dermatitis to Epoxy Resin

“…13,14 In particular, many patients have a history of other types of dermatitis such as ACD for many years preceding development of photosensitivity. 16,17 Allergic contact dermatitis to sesquiterpene lactone was not found in the 2 of 5 patients in our series patch tested to this allergen, nor was photo-ACD found in cases 2 and 3 patch tested to musk ambrette. It is most commonly described with ACD to sesquiterpene lactone 15,16 and photo-ACD to musk ambrette.…”

Evidence and conjecture about mechanisms of cutaneous disease in photodermatology

“…Research into some of the other photosensitivity syndromes thought to be due to photoallergens has been limited. Chronic actinic dermatitis (CAD) has a distinctive immunological pathogenesis as symptoms often occur after contact dermatitis or drug induced photoallergy . Furthermore, after the drug is stopped, the photosensitivity persists and further exposure to the initiating allergen may not be required for subsequent photosensitivity.…”

“…Furthermore, after the drug is stopped, the photosensitivity persists and further exposure to the initiating allergen may not be required for subsequent photosensitivity. The contact allergens have in the past been specific to plants of the daisy family, the sesquiterpene lactones . A possibility is that certain types of contact allergen, in some way, predispose to a UV‐induced photoallergy.…”

Photodermatoses in India

“…[17,18] Photocontact dermatitis secondary to P. hysterophorus too has been reported. [19] This is probably due to its profuse and widespread growth and its high sensitizing property.…”