Sebaceous adenitis

The sebaceous adenitis (English sebaceous adenitis, SA; granulomatous sebaceous adenitis also, primary sebaceous adenitis or aseptic sebaceous adenitis ) is a disease in dogs and cats, in which the sebaceous glands of the skin are irreversibly destroyed by an inflammatory reaction. It belongs to the idiopathic diseases, ie diseases whose root cause is unknown. But it is believed that the sebaceous adenitis is genetic.

Sebaceous adenitis is derived from the Latin glandula sebacea, sebaceous gland, and adenitis, glandular inflammation.

Pathophysiology

There are several hypotheses on the causes of the disease. These range from a genetic developmental disorder of the sebaceous glands on the hypothesis of autoimmune reactions that destroy the sebaceous glands to keratinization, which lead to mastitis. Also a genetic immune disorder is a possible explanation.

The disease is initially accompanied by an inflammation of the sebaceous glands. Later, these perish, resulting in hyperkeratosis. The hair follicles are affected in their development, but not completely destroyed.

Clinic

Signalment

The disease is described in dogs and cats. In dogs it occurs in the breeds poodles, Magyar Vizsla and some Nordic breeds such as Akita and Samoyed frequently, even with Hovawart, Schnauzer, German Shepherd Dog, Bernese Mountain Dog, Maltese, English Springer Spaniel and half-breeds comes before them. The disease occurs in some breeds and littermates heaped on, for example, the Akita and Hovawart. Overall, cases have been reported in more than 50 races.

Symptoms

The disease manifests itself often initially limited by progressive hair loss, locally. Hairless they are dry and scaly. Tufts of hair are often glued together and have Keratinmanschetten. Also typical is an excessive keratinization of the skin ( hyperkeratosis). In various breeds have different typical course of the disease. Itching is not always available and less pronounced, it only occurs with secondary infections.

Peracute disease processes often precede gastrointestinal problems, sometimes they occur together with food allergies. Many affected animals have inflammation of the ear canal by increased formation of cerumen (otitis externa ceruminosa ).

Diagnosis

The diagnosis is made by taking a skin biopsy with subsequent histology and demonstrate the lack of sebaceous glands and / or lymphocytic inflammation in the area. Differential diagnosis, especially infections caused by bacteria, parasites and fungi must be excluded. Also Malassezia dermatitis and vitamin A -responsive dermatosis differential diagnosis consideration.

In addition to the aseptic form there is a secondary form of SA, which is caused by Leishmania. Unlike the primary form of the sebaceous glands can regenerate here. However, some authors limits on this form of SA, so count them exactly not to do so.

Treatment and prognosis

A causal therapy does not exist. The administration of cyclosporin A can stop the disease, but after stopping the destruction of the sebaceous gland continues to progress. In mild forms of the disease, a therapy with shampoos that contain keratinlösende agents succeed. It seems that a treatment in the ( early ) inflammatory phase of the disease is more promising than in the (late) chronic phase. There are authors who recommend this reason, to begin treatment with cyclosporine as early as possible. No difference between the effect of local treatment and that of a systemic therapy in an international study could be detected.

Genetics and breeding hygiene

The exact mode of inheritance of SA is not known; but its occurrence in certain breeds and in siblings of affected dogs suggests that it is a hereditary disease with her. Affected animals should therefore not be used for breeding.