"We did a patch test on all patients, who had classical cosmetic dermatitis
and those with induced skin darkening (pigmented cosmetic dermatitis
)", said Riti Bhatia, Dermatologist, AIIMS, Rishikesh.
Keywords: Cosmetic dermatitis, beauticians, hairdressers, occupational dermatoses, hair dye, p-phenylenediamine (PPD).
Most of these substances contain ingredients capable of causing sensitization of the skin, thus leading to cosmetic dermatitis. Various researchers have reported prevalence rates of cosmetic dermatitis ranging from 4-9% in the general population.2
A recent study of cosmetic dermatitis in the US has revealed that out of 10,061 patients, 23.8% females and 17.8% males had positive patch test to at least one allergen from cosmetic source.3 The clinical picture of cosmetic dermatitis depends on the type of products used (and, consequently, the sites of application), exposure, and the patient's sensitivity.
The most common patterns of cosmetic dermatitis observed were contact dermatitis localized to face in 80 patients followed by dermatitis of scalp in 47, hands in 26 and disseminated dermatitis in 8 patients (Figure 1 and 2) (Table 4).
On performing patch test, 79 (56.4%) patients showed positive reaction to one or more allergens, thus confirming the diagnosis of allergic cosmetic dermatitis. In total, 3100 allergens were applied and out of these, 91 (2.9%) gave a positive reaction.
Pigmented cosmetic dermatitis, as proposed by Nakayama et al.
Cetrimide is an antiseptic and major formulation excipient chemical in cosmetics and reported to elicit positive reactions in 12% of 50 patients with cosmetic dermatitis .
Thiomersal is considered uncommon allergen and the reported thiomersal contact sensitivity in patients of cosmetic dermatoses or pigmented cosmetic dermatitis varies from 8% to 77% [19-21].
Bronopol caused contact sensitization in one of 202 patients with cosmetic dermatitis in another series .
"Methylisothiazolinone should be considered as a potential suspect allergen among patients with suspected cosmetic dermatitis
, facial dermatitis, and sunscreen allergy" the authors said, concluding that the addition of MI to an allergen screening series "will likely uncover otherwise undiagnosed cases of preservative contact allergy."