It delays healing of the skin by becoming a mechanical barrier to migration of dermal cells across the defect. Treatment includes surgical or chemical removal of the excess tissue and medication to prevent regrowth while the skin bridges the defect. Chemical irritants such as urine, feces, or human-applied substances like mustard oil or ginger can produce profound skin problems. This chemical can produce a profound skin inflammation. Sunburn also can be a direct trauma to the skin, a symptom of underlying disease, or an effect of the presence of certain medications in the dermis.
Sunburn often occurs on the muzzle, around the eyes, and on white-skinned regions.
Prevention, as in humans, is mainly by limiting exposure to direct sunlight. Sunblock creams made for humans work well on horse muzzles, although the protectant must be replaced frequently for maximal effect. Sunburned skin will peel, and it takes a week or so to heal. Skin burned due to systemic disease is called photosensitization. It usually is related to diseases involving the liver and can be diagnosed with a blood test.