MIAMI - Patients with a strongly positive patch test result for the most common sensitizer in hair dye, para-phenylenediamine, also demonstrate cross-reactivity to some other hair dye components, according to a retrospective study.
"Basically we wanted to see if our 3+ reactors had strong cross-sensitivity to other compounds, versus our 1+ or 2+ positive PPD [para-phenylenediamine] patients." Dr. Lauren Fratesi said at the annual meeting of the American Contact Dermatitis Society.
Dr. Fratesi reviewed data for 134 patients with a PPD contact allergy. All patients had a significantly positive reaction (from 1+ to 3+) at an Ottawa outpatient contact dermatitis clinic between May 1997 and July 2009. The group was 76% female, and 13% were professional hairdressers.
Patients were assessed using 50-70 patch test allergens in the North American Contact Dermatitis Group standard series, as well as 7 allergens in the Chemotechnique hairdressing series. A total of 18% had a 1+ reaction, 19% had a 2+ reaction, and 63% had a 3+ reaction to PPD.
Slightly more than 90% were sensitized through hair dye; 2%, through henna tattoos; and 8%, from other sources of PPD. Not surprisingly, the face and neck were the most often affected areas, reported by 72% of the patients. A majority, 86%, used topical steroids to treat their allergic reactions. Oral corticosteroids were taken by 41%.
A significant relationship was found between the severity of the PPD reaction and cross-reactivity to other hair dyes, including 2,5-diaminotoluene (31% of patients) and 3-aminophenol (19%), said Dr. Fratesi, a dermatologist at the University of Ottawa.
In contrast, there was no significant relationship with prevalence of reactions to sulfa drugs (6%), benzocaine (8%), or black rubber/IPPD (N-isopropyl-N'-phenyl-paraphenylenediamine, 1.5%).
Dr. Fratesi reported no relevant financial disclosures.