Parakeratosis

Clinical importance

Parakeratosis is a nutritional noninfectious disorder. It is characterized by a nonpruritic, crusting dermatitis, similar to exudative epidermitis. This disease is unlikely in commercial swine, unless some error occured in the design or manufacturing of the diet. Growing pigs between two and four months of age tend to be more affected.

Etiology/Cause

Parakeratosis is caused by deficiency of zinc and essential fatty acids in the diet. Additional causes include high levels of calcium decreasing zinc absorption.

Associated symptoms

Crusty lesions on the abdomen, distal portion of the legs, and medial thighs are characteristic of parakeratosis. The skin may be dry and rough, with dirt and debris accumulating in the lesions. In severe cases, reduced growth rate and appetite are seen, occasionally accompanied by vomiting and diarrhea. There are great individual differences in the duration and symptoms of this disease. On the same diet, some pigs may be severely affected while other pigs may show mild or no symptoms. Pruritus is rare.

Associated lesions

Macroscopic lesions
The lesions begin as redding of the skin, that quickly forms dry, scab-like crusts. The skin can thicken and fold, which causes debris to accumulate along with moist brownish sebum.

Diagnosis

Skin biopsy for histopathology is the common test for determining parakeratosis. Zinc levels in the liver and in the serum may be decreased.

Differential Diagnosis

When facing crusty lesions and other symptoms of parakeratosis exudative epidermitis, sarcoptic mange, and vitamin B deficiency must also be considered.

Treatment, Prevention and Control

Correcting the zinc and calcium levels of the diet produces a fast response. Feed quality control is the best way to prevent parakeratosis.