Clinical signs
IBH is characterized by skin sensitization followed by severe itching that leads to localized hair loss and excoriations of the skin. This can then contribute to development of secondary bacterial infections. The lesions are often localized along the dorsal midline of the horse at the base of the mane and the tail area. The horses have temporary remission during the winter, but the symptoms re-appear in the spring with the midges and are then frequently worse (for review Schaffartzik et al., 2012). IBH impairs seriously the health of the horses and is an animal welfare issue.
Presently, there is no available curative treatment for IBH. The only way of preventing or reducing the eczema is to avoid the midges, use blankets and stable the horses around dawn and dusk. Symptomatic treatment with corticosteroids is used in severe cases.