Changes

==Clinical signs==

==Clinical signs==

Skin lesions are seen most commonly in non-pigmented areas at the palmar or plantar aspect of the pastern. Hindlimbs are most commonly affected and lesions are often symmetrical. The dermatitis is initially characterised by erythema, alopecia, exudation, pruritus and crusting of the lower limb. Lameness may occasionally be a feature of the condition. In chronic cases, thickening of the skin occurs with hyperkeratosis and fissure formation.

Skin lesions are seen most commonly in non-pigmented areas at the palmar or plantar aspect of the pastern. Hindlimbs are most commonly affected and lesions are often symmetrical (although they make affect only one limb). The dermatitis is initially characterised by erythema, alopecia, exudation, pruritus and crusting of the lower limb. Lameness may occasionally be a feature of the condition. In chronic cases, thickening of the skin occurs with hyperkeratosis and fissure formation.

==Diagnosis==

==Diagnosis==

The seasonal nature of the condition combined with a history of continual wetting may aid in diagnosis. However, the list of differential diagnoses for this condition is lengthy and several important conditions should be ruled out. If lesions are restricted to non-pigmented skin only, liver enzymes and bile acids should be evaluated in order to rule out photosensitisation as a cause of disease. Skin scrapes should be performed in order to rule out parasites such as Chorioptes mites (especially in heavily-feathered horses). Bacterial swabs for culture and skin biopsy may be useful in refractory cases.  

A detailed history is important in order to aid in determining the underlying cause of the condition. A detailed description of the environment (bedding, quality of turnout, exposure to wet conditions) is particularly important. The seasonal nature of the condition combined with a history of continual wetting may aid in diagnosis. However, the list of differential diagnoses for this condition is lengthy and several important conditions should be ruled out. If lesions are restricted to non-pigmented skin only, liver enzymes and bile acids should be evaluated in order to rule out photosensitisation as a cause of disease. Skin scrapes should be performed in order to rule out parasites such as Chorioptes mites (especially in heavily-feathered horses). Bacterial swabs for culture and skin biopsy may be useful in refractory cases.  

In chronic cases, diagnosis may be difficult and a diagnosis of idiopathic pastern dermatitis is often made.

In chronic cases, diagnosis may be difficult and a diagnosis of idiopathic pastern dermatitis is often made.