Photo-patch and patch tests in patients with dermatitis over the photo-exposed areas: A study of 101 cases from a tertiary care centre in India.
BACKGROUND
Many patients with dermatitis over photo-exposed body areas are positive to many contact allergens and have a pre-existing allergic contact dermatitis.


METHODS
This study included patients who presented to a tertiary centre in India with dermatitis on photo-exposed body areas suspected of chronic actinic dermatitis. Their detailed histories were recorded and cutaneous and systemic examinations were performed. Patch testing was done in all the patients and photo-patch testing was carried out in 86 patients.


RESULTS
Altogether 101 patients were included (69 males, 32 females). The most common presentation was lichenified hyperpigmented plaques on the photo-exposed sites. Photosensitivity was recorded in 64 (63%) patients and summer exacerbation in 52 (52%). Exposure to the Parthenium hysterophorus weed was recorded in 70 (69%) patients, 27 (26.7%) had a history of hair dye application and 20 (20%) had a history of atopy. Photo-patch test was positive in 11 (12.8%) patients and patch testing was positive in 71 (70%). Parthenium hysterophorus was the most common allergen implicated and was positive in three (4%) photo-patch and 52 (52%) patch tests. Other positive photo-patch test allergens were perfume mix, balsam of Peru, thiuram mix, Compositae mix and promethazine hydrochloride. Other common patch test allergens were parthenolide, colophony, fragrance mix and p-phenylenediamine (PPD) base.


CONCLUSIONS
In the Indian population parthenium and perfume mix are the most common photoallergens in patients with dermatitis over photo-exposed areas, while parthenium, colophony, fragrance mix and PPD are the common positive allergens.
Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Vinod Kumar
VK
Sharma
Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Neetu
N
Bhari
Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Ashok Roopchand
AR
Wadhwani
Dermatology and Venereology, All India Institute of Medical Sciences, New Delhi, India.
Riti
R
Bhatia
D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects*; D019659:Asteraceae / Q000009:adverse effects; D001453:Balsams / Q000009:adverse effects; D005260:Female; D006801:Humans; D017495:Hyperpigmentation / Q000209:etiology* / Q000473:pathology; D007194:India; D008297:Male; D008875:Middle Aged; D010312:Parthenogenesis; D010328:Patch Tests / Q000379:methods; D010476:Perfume / Q000009:adverse effects; D010787:Photosensitivity Disorders / Q000209:etiology* / Q000473:pathology; D010936:Plant Extracts / Q000009:adverse effects; D013472:Sunlight / Q000009:adverse effects; D062606:Tertiary Care Centers; D013893:Thiram / Q000009:adverse effects; D055815:Young Adult; D000097762:Parthenium hysterophorus
D000485:Allergens; D001453:Balsams; C519376:Parthenium hysterophorus extract; D010476:Perfume; D010936:Plant Extracts; D013893:Thiram; C025080:Peruvian balsam
chronic actinic dermatitis; dermatitis over photo-exposed areas; patch test; photo-patch test