Sweet itch

The disease known as summer mange or summer eczema occurs in horses mainly in the warm season and is the result of an allergic reaction to the saliva of stinging insects such as gnats (Culicoides spp.), black flies (Simulium spp.), mosquitoes (Culex spp.), gadflies (Stomoxys sp.) or horseflies (Tabanus spp.). It occurs most frequently at transitional areas of the coat, i.e. at the mane crest or at the tail rump. The constant rubbing causes the hair to fall out at first. The skin areas can secondarily become infected with bacteria and fungi. But the constant rubbing can also lead to bloody and purulent inflammations and barky scabs. This in turn attracts more insects, which reinforces the vicious circle. The usual treatment is primarily to keep insects away using repellents or even full body blankets. Persistent itching is treated exclusively with parenteral corticosteroids and local skin ointments or lotions against secondary infections.