Loose Anagen Hair Syndrome in Two Patients with Epidermolysis Bullosa Simplex, Dowling-Meara Type

The document reports on two patients with epidermolysis bullosa simplex, Dowling-Meara type (EBS-DM), who also presented with loose anagen hair syndrome (LAHS). EBS-DM is characterized by widespread blistering, particularly severe during infancy, while LAHS is identified by the painless extraction of anagen hairs that lack an external root sheath and show cuticle ruffling. The first patient, a 7-year-old Portuguese girl, had thin hair that rarely needed cutting, and microscopic analysis of her hair revealed characteristics of LAHS. The second patient, a girl of Polish, Ukrainian, and French Canadian descent, had fine, blonde hair that also seldom required cutting, and a hair pluck test showed similar LAHS features. Both patients shared the same keratin 14 mutation (N123S), which is involved in the structural support of the epidermis and hair follicle. The presence of both EBS-DM and LAHS in these patients with the same keratin 14 mutation suggests a potential common pathogenesis for both disorders. The study implies that understanding LAHS pathogenesis may clarify this relationship. No specific number of participants beyond the two case studies is mentioned, indicating a very limited scope for generalizing the findings.