An IL17RA frameshift variant in a Holstein cattle family with psoriasis-like skin alterations and immunodeficiency.

BACKGROUND: Skin lesions and dermatoses in cattle are often associated with infections due to bacteria, fungi or environmental risk factors. Dermatoses with genetic etiology have been described in cattle. Among these rare disorders, there are primary congenital dermatoses that are associated with inherited nutritional deficiencies, such as bovine hereditary zinc deficiency or zinc deficiency-like syndrome. This study presents three cases of Holstein cattle with congenital skin lesions observed on a single farm that resemble zinc deficiency-like syndrome. Close clinical and pathological examinations took place in two cases. Pedigree analysis indicated autosomal recessive inheritance and whole-genome sequencing of both affected calves was performed. RESULTS: The two calves showed retarded growth and suffered from severe ulcerative dermatitis with hyperkeratosis, alopecia furunculosis and subcutaneous abscess formation. Blood analysis showed correspondent leukocytosis with neutrophilia whereas minerals, macro- and micronutrients were within the reference ranges. Variant calling and filtering against the 1000 Bull Genomes variant catalogue resulted in the detection of a single homozygous protein-changing variant exclusively present in both sequenced genomes. This single-nucleotide deletion in exon 3 of IL17RA on bovine chromosome 5 was predicted to have a deleterious impact on the encoded protein due to a frameshift leading to a truncated gene product. Genotyping of the affected cattle family confirmed recessive inheritance. CONCLUSIONS: A loss-of-function mutation of the IL17RA transmembrane protein could be identified as most likely pathogenic variant for the psoriasis-like skin alterations observed in the two affected Holstein calves. In man, rare recessive diseases associated with IL17RA include immunodeficiency 51 and chronic mucocutaneous candidiasis. This supports the observed immunodeficiency of the presented cases. This study reports the first naturally occurring IL17RA-associated animal model.

Palmoplantar nonpustular psoriasiform dermatitis in a rhesus macaque.

A case of psoriasiform dermatitis in an adult male rhesus macaque is reported. Appearing spontaneously, the condition presented the clinical and histopathological features of human palmoplantar nonpustular psoriasis. The animal developed multiple scaly plaques on his palms and soles, as well as nail hyperkeratosis and widening of the nail root. Microscopically, the skin lesions showed epidermal hyperkeratosis with multifocal parakeratosis, neutrophil microabscesses in the stratum corneum, a loss of granule cell layer under the microabscesses, acanthosis, and elongation of the rete ridges; the superficial dermis showed a dense inflammatory infiltrate containing lymphocytes, macrophages and neutrophils, as well as dilated and tortuous blood vessels. The lesions improved for 15 days after intramuscular corticosteroid depot therapy and worsened slightly afterwards. Later, a spontaneous, progressive remission coincided with the beginning of spring and lasted until the end of summer; the skin lesions practically disappeared during this period, and the nails looked nearly normal. During the next autumn and winter only nail hyperkeratosis was present. Serum analyses showed hyperproteinaemia and hyperglobulinaemia during the outbreak phase and normal values during remission. The clinical and histopathological features of this case, as well as its evolution, are compared with the three other reported cases of psoriasiform skin lesions in nonhuman primates. To the authors' knowledge, this is the first report of a definite palmoplantar nonpustular psoriasiform dermatitis in a rhesus macaque.

Psoriasiform-lichenoid-like dermatosis in three dogs treated with microemulsified cyclosporine A.

Cyclosporine has been reported to be effective for the treatment of various cutaneous autoimmune disorders in dogs. Adverse reactions have generally been limited to gastrointestinal tract disturbances and cutaneous eruptions. The article describes antimicrobial-responsive cutaneous reactions in 3 dogs being treated with microemulsified cyclosporine A because of various dermatologic conditions. Cutaneous reactions in these dogs were similar to psoriasiform-lichenoid dermatitis and may represent an atypical staphylococcal infection.

[Psoriasis in a female chimpanzee]. / Psoriasis bei einem Schimpansenweibchen.

Psoriasis, a widespread genodermatosis in Homo sapiens, also appears in primates. We report on a female chimpanzee in Leipzig Zoo. After years of captivity the animal developed erythematosquamous, highly hyperkeratotic, lesions, some confluent, on the knees, elbows, back of the hands and feet and on the forearms and the seat, which showed histologically characteristic features of psoriasis. It may be that both previous infections and psychic stress resulting from social isolation had caused eruption of the disease. In the literature single cases of psoriasiform dermatoses have also been described in other species of monkeys and even in a springer spaniel. Nonetheless, the search for an animal model of psoriasis vulgaris is still going on.

Psoriatic plaques in Macaca fascicularis.

An adult male cynomolgus monkey (Macaca fascicularis) developed erythematous plaques with adherent white scales on the skin. Microscopically, the epidermis had regular acanthosis with marked parakeratosis, focal absence of stratum granulosum, and spongiform pustules and Munro-like microabscesses. These histologic findings were suggestive of psoriasis vulgaris.

Characterization of lichenoid-psoriasiform dermatosis of springer spaniels.

Three unrelated Springer Spaniels were examined because of chronic dermatitis. Their ages at onset of clinical signs were 4, 5, and 18 months. The initial lesions consisted of erythematous papules and plaques, with corrugated surfaces in the ear canal and in the inguinal area. Later, papules, scale, and adherent keratin mounds developed inside the ear, in the inguinal area, around the mouth, eyes, and anus, and occasionally on the thoracic wall and the limbs. In one case, the nose was involved and there was accompanying depigmentation. The disease waxed and waned for the 10-month, 18-month and 3-year periods of observation, with various treatments proving unsuccessful. Corticosteroids at high doses and antibiotics appeared to mitigate the severity of the disease. Histopathologic interpretation enabled classification of the disease process within both psoriasiform and lichenoid tissue reactions. In view of the apparent breed predisposition and the gross and microscopic appearance of the lesions, it was proposed that the name for this disease be lichenoid-psoriasiform dermatosis of Springer Spaniels. This disease would be clinically classified as seborrhea and could be differentiated within this group by the presence of erythematous papules and plaques along with accurate histologic assessment.

Psoriasiform dermatosis in a rhesus monkey.

We describe a dermatosis in a rhesus monkey (Macaca mulatta) that has the characteristic features of the human skin disease, psoriasis vulgaris. The monkey was affected by chronic erythematous, scaling plaques that occurred on the scalp, face, dorsal back, the extensor aspects of the limbs and the palms and soles. Subungual hyperkeratosis was present. Skin biopsies of the affected skin showed a regular acanthosis with reduction of granular cell layer, parakeratosis and supra papillary thinning of the epidermis. Foci of inflammatory cells were seen in the upper epidermis. The dermal changes were tortuous capillary loops and benign inflammatory infiltrate, particularly in the papillary dermis, all of which are features of the human skin disease psoriasis vulgaris. The presence of a nutritional deficiency syndrome was excluded and there was no evidence of any systemic disease.