Allergic contact dermatitis from hair dye and development of lichen simplex chronicus.

Those who dye their hair frequently manifest allergic contact dermatitis (ACD) from p-phenylenediamine (PPD)-containing hair dye. PPD is known to be the most frequent sensitizer in hair dye, but there has been no documentation of this sensitizer having a role in chronic dermatologic conditions. Our department experienced a case of a 62-year-old woman with lichen simplex chronicus (LSC), who complained of aggravation after hair dyeing and made such an association.

Genetic polymorphism of cytochrome P450 2C9 in diphenylhydantoin-induced cutaneous adverse drug reactions.

Background: Apart from allergic mechanisms, a lack or mutation of metabolic enzymes may cause adverse drug reactions. Patch testing has rarely been useful in cutaneous adverse drug reactions (CADRs) induced by diphenylhydantoin (DPH). Genetic polymorphisms leading to altered metabolic processes of cytochrome P(450) (CYP) 2C9, a main metabolic enzyme for DPH, may be the pathological mechanism for certain cases of DPH-induced CADRs.

Patch testing with carbamazepine and its main metabolite carbamazepine epoxide in cutaneous adverse drug reactions to carbamazepine.

The value of skin tests in the diagnosis of adverse drug reactions (ADRs) has been limited. Lack of knowledge as to the nature of drug allergens has contributed to these limitations. Several reports have addressed the roles of metabolites in cutaneous ADRs and skin testing.

Insulin-induced drug eruptions and reliability of skin tests.

Allergic reaction to insulin preparations seemed to have decreased since the introduction of contaminant-free, human preparations. The role of protamine sulfate in decreasing the prevalence of allergy is unclear. This study examines the causative components of insulin allergy along with the value of skin tests for diagnosis.