Epidemiological characteristics and identification of specific allergens in patients with footwear contact dermatitis attending the Dermatology Clinic, Base Hospital Karawanella

Footwear contact dermatitis is a common type of allergic contact dermatitis in Sri Lankan patients attending dermatology clinics. Only a few studies have looked at the specific allergens causing footwear contact dermatitis in Sri Lanka.

Our objective was to identify the specific allergens responsible for footwear contact dermatitis in a population of patients attending a dermatology clinic in Sri Lanka.

Sixty nine consenting adults with a clinical diagnosis of footwear contact dermatitis at the Dermatology Clinic, Base Hospital Karawanella, were enrolled. Following clinical examination and counseling they were subjected to a patch test using the European Baseline series by Chemotechnique Laboratories, Sweden. The 96 hour reading was used for the analysis.

Sixty nine participants, the majority (51.6%) aged between 31 and 50 years, were included with 40 (57.9%) females and 29 (42.1%) males. 29.7% were housewives.

Only the feet were involved in75%. Other atopic manifestations were found in 40%. The commonest type of footwear was black rubber slippers (76%) and the majority wore footwear for less than 8 hours a day.

There were 9 negative patch tests. The commonest haptens in order of frequency were mercaptobenzothiazole (65.21%), mercapto mlx (53.62%), thiuram mix (31.88%), potassium dichromate (24.63%) and nickel II sulphate hexahydrate (18.84%).

The commonest allergens in patients with footwear contact dermatitis are rubber related products indicating the practices of footwear usage in the population.