Langerhans cells in allergic contact dermatitis.

Allergic contact dermatitis (ACD) is a common skin disease that has significant socio-economic impact. ACD is mediated by a T-cell mediated inflammatory reaction. Langerhans cells (LCs) are an epidermal DCs subset specialized in antigen presentation. After hapten exposure, LCs play a major role as in induction adaptive immune response against allergens. LCs recognize, take up and process haptens and migrate to the local draining lymph nodes. However, LCs specific functions and the LCs migration to local draining lymph nodes are not yet clearly defined. Recent advance in the knowledge of LCs function has increased in the past decades including the evidence for a tolerogenic function of LCs. The present review will focus on the role for LCs response to contact allergens.