Itching skin is the first and the most typical symptom of allergic skin. Allergy can have many causative agents. Insect bites cause allergic reaction to majority of the horses, even though only minority has summer eczema. Difference between the summer eczema horses and horses reacting allergically is the intensity of the symptoms and required treatment.
Veterinarian can best evaluate with you what is your horse allergic to and estimate the comprehensive clinical situation and define the right treatment.
Summer eczema is the most common allergic skin condition in horses. Horses are over sensitive to the saliva of the Culicoides insects, also called midges. These tiny insects live in wetland, by standing water (e.g. ditches) and are poor fliers, in dark they do not fly at all.
The allergic inflammation is an oversensitive reaction of the skin characterized by warmth, redness and with time hardening of the skin. Allergic inflammation causes itching, which causes horses to rub.
The rubbing cause further damage on skin, which can be infected. Head, ears, mane, tail and the dorsal midline are the symptomatic areas. The severity of the disease tend to worsen over time, specifically if the treatment is not sufficient.