Allergic contact dermatitis to para-phenylenediamine

Area of Science:

• Dermatology
• Allergology
• Toxicology

Background:

• Para-phenylenediamine (PPD) is a frequent cause of hair dye allergy.
• Australian data on PPD allergy prevalence and patient outcomes is limited.
• Patients often seek alternatives to PPD-containing hair dyes due to dissatisfaction with avoidance advice.

Purpose of the Study:

• To investigate the characteristics and outcomes of patients with PPD allergy in Australia.
• To analyze patch test results and identify co-allergens.
• To review hair dye allergy science and explore alternative hair dye options.

Main Methods:

• Retrospective analysis of patch test data from 2006-2013 at Liverpool Hospital Dermatology Department.
• Inclusion of 584 patients undergoing patch testing.
• Review of scientific literature on hair dye allergy and alternative products.

Main Results:

• An Australian PPD allergy prevalence rate of 2% (11 out of 584 patients) was identified.
• Approximately 50% of PPD-allergic patients also reacted to para-toluenediamine (PTD).
• 78% of affected patients tried alternative hair dyes, with over half continuing to dye their hair.

Conclusions:

• PPD allergy significantly impacts patients' lifestyles.
• Alternative non-PPD hair dyes exist but require careful selection due to potential cross-reactivity, especially with PTD.
• Ongoing vigilance and informed choices are crucial for managing hair dye allergies.