Related Experiment Video
Updated: Jan 8, 2026
A Mouse Ear Model for Allergic Contact Dermatitis Evaluation
Published on: March 24, 2023
Changes in Contact Dermatitis Allergen Profile in Chronic Actinic Dermatitis: Results From a Single Centre
Ying Xin Teo1,2, Louise Cunningham1, Hiva Fassihi3
1Department of Cutaneous Allergy, St John's Institute of Dermatology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
Background:
Chronic actinic dermatitis (CAD) is a photodermatosis associated with contact allergy. Changes in the contact allergen profile in patch-tested CAD patients from our department have been reported over several decades.
Objectives:
To determine the frequency of positive patch tests and allergen profiles in recently investigated CAD patients and compare this to profiles in earlier decades.
Methods:
A retrospective cohort study was undertaken at a tertiary Cutaneous Allergy department between 2011 and 2021. Demographics and 10 allergens with highest positivity in CAD and non-CAD patients were compared.
Results:
Patch testing was performed in 309 (88.3%) of 349 CAD patients, with 186 (60.2%) testing positive to any allergen and 8 (2.6%) positive on photo-patch testing. Patients aged > 40 and with Fitzpatrick skin type V-VI were statistically more likely to be patch test positive (age > 40: p = 0.0082; Fitzpatrick skin type: p = 0.0361). Sesquiterpene lactones (SQL) (6.8%) and formaldehyde (4.8%) were amongst the top 10 most frequently positive allergens in CAD but not in non-CAD patients.
Conclusion:
Allergic contact dermatitis remains prevalent amongst CAD patients, although sensitisation to allergens historically linked to CAD is decreasing. The cause of this is unclear but potentially due to changes in environmental exposures, particularly in younger CAD patients.
