Mohammad A. Al-Shami
Department of Dermatology at the Faculty of Medicine and Health Sciences, Sana'a University, Yemen
As human life becomes increasingly complex, our skin is exposed to an ever-increasing spectrum of chemical and biological products. Inevitably, the incidence of allergic sensitization is showing a steady rise. There have been no large-scale population-based studies of contact sensitization in Yemen; however, Yemen is ready for a contact sensitization "explosion" due to high level of pollution and absent or poor labeling laws.
Allergic contact dermatitis (ACD) develops in only a small proportion of sensitized individuals and population estimates vary from 1.7 to 6%
[1,2] However, the true incidence of ACD in a society is very difficult to estimate since its diagnosis depends on several factors such as the demographic profile of patients, local industrial development, index of suspicion of the
physician, and availability of patch testing . Allergic contact dermatitis (ACD) is a very challenging problem in the dermatology praxis with considerable morbidity and economic impact. ACD, together with irritant contact dermatitis, comprises 6-10% of all dermatology clinic visits.[1,4] ACD is a delayed type hypersensitivity reaction, which develops in predisposed individuals as a consequence of environmental exposures to allergens.[5,6,7] The total number of sensitized individuals in the population mainly depends on the degree of cutaneous exposure, although it appears that some persons are more easily sensitized to common haptens than others, probably due to their genetic background.[8,9]
The patch-test has been established as a useful tool for the detection of allergic contact dermatitis and for exact