Pênfigo foliáceo em um gato de oito meses de idade: possível reação cutânea adversa a fármacos?

Background: Pemphigus foliaceus is an autoimmune skin disease whose the occurrence in feline clinic is uncommom. The etiology is unknown in most cases. Althought it is a rare condition in cats, pemphigus foliaceus can be induced by drugs. It may affect both adult and old cats with no sexual or racial predilection and diagnosis is based on animal historical, clinical examination and skin histopathology. Moreover, the treatment consists in immunosuppressive-based drugs. This paper describes a pemphigus foliaceus case in an eight-month-old kitten, probably due a cutaneous adverse drug reaction.Case: A 8-month-old, neutered male mongrel cat with crusted lesions located on face was examinated at the Veterinary Hospital. The owners reported that they had adopted the patient two months before the clinical presentation suggesting that this background was unknown. The cat was treated in a local veterinary clinic with antibiotics and anti-inflammatory for rhinotracheitis and herpetic dermatitis on face due to the occurrence of sneezing and crusted pruriginous dermatitis. The kitten presented erosions, purulent exudation and crusts on pinnae, nasal and supra ocular areas, paronychia with purulent exudate and alopecia at distal portion of the tail. Supplementary exams such as skin scraping, cytology and fungal culture were performed to rule out other agents and confirm the diagnosis. The parasitological and fungal examination resulted negative despite the fact that cytological exam showed coccoid bacteria. Complete blood count and biochemical profile showed no alteration and the test for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) resulted negative. Histological changes were consistent with intra-epidermal pustular subcorneal with acantholysis dermatitis. An immunosuppressive dose of prednisolona was prescribed for 15 days. After this time, the crusted lesions were substituted by alopecia areas. Every 20 days the corticosteroid dose was reduced by half and after 90 days, the patient showed repilation in all regions previously affected during 545 days whithout treatment.Discussion: Pemphigus foliaceus is usually an idiopathic disease but in some cases it may be induced by drugs and infectious or parasitic agents. Previous reports described that animals younger than 1 year-old and older than 17 year-old can be affected. However, the disease occurrence is rare in young cats. The age of onset of symptoms was early considering that the literature describes 5 years of age as an average for the starting of the disease. Pemphigus foliaceus is considered a pustular disease. However, pustule is rarely reported in cats in contrast with crusted lesions which are the most common clinical sign. The body regions affected were the same as reported in the literature with the addition of systemic signs as anorexia and lethargy. Fungal culture and parasitological examination should always be performed in cats with clinical evidence to discharge other agents. Diagnosis is made by skin histopathology in which acantholytic cells are the main characteristic. The importance of the differential diagnosis and skin biopsy regardless of age enabled the diagnosis and therapeutic success. It is suggested that Pemphigus foliaceus was of pharmacodermic etiology because of the age of the patient, a history of administration of unknown antimicrobial medication and the lack of recurrence of clinical manifestations after 545 days of the end of glucocorticoid treatmen

Occurrence of Cutaneous Neoplasia in Dogs with Actinic Dermatitis in a Veterinary Medical Teaching Hospital - UFRGS, Brazil

Background: Actinic dermatitis is an environmental skin disease resulting from excessive exposure to ultraviolet light irradiated by the sun. This phototoxic reaction affects dogs and cats, particularly with short hair and lightly pigmented skin, exposed to sun light. Primary lesions are typical from a sunburn and chronic exposure, and may induce to a premalignant lesion known as actinic keratosis, which may develop to neoplasms. The aim of the present study was to describe a retrospective study of actinic dermatitis and the occurrence of cutaneous neoplasia in dogs presented to a Veterinary Medical Teaching Hospital (HCV/UFRGS) in Porto Alegre, Rio Grande do Sul, Brazil in a period of 10 years.Materials, Methods & Results: A retrospective review of medical records from January 2009 to December 2019 was performed to identify dogs with actinic dermatitis. Twenty-eight dogs were diagnosed based on a history of sun exposure and skin lesions including erythema, scaling, comedones, thickened skin, hyperpigmentation, ulceration and/or secondary infections on poorly pigmented skin. In addition, in twelve dogs (42.8%) the disease was also confirmed by histopathology. Cutaneous lesions locations were previously defined as head, limbs, neck and trunk. The head was subdivided in chin, ears, face, lips and nasal plane; the limbs in pelvic and thoracic; and the trunk, in abdomen, dorsal pelvis, perianal and thorax.  All 28 dogs diagnosed with actinic dermatitis in the study had been chronically exposed to solar radiation and had light skin and coat. Dogs were between 3 and 20 years old, mean 7.6 years and median 7 years, mostly female dogs (64.2%) and neutered or spayed (64.2%). The most affected breeds were American Pitbull Terrier (35.7%) and Boxers (28.5%). Other breeds were Bull Terrier, Dalmatian, Dogo Argentino and Scottish Terrier. In 15 cases, tumors were confirmed by cytopathology or histopathology, resulting in 9 different skin tumors and two types of cysts (epidermoid and follicular). Among these, the most prevalent malignant neoplasm was squamous cell carcinoma (66.7%), followed by mast cell tumor (40%), hemangiosarcoma (26.6%), and basal cell carcinoma (6.6%). Five benign tumors were identified: hemangioma (13.3%), fibroma (6.6%), lipoma (6.6%), sebaceous adenoma (6.6%) and trichoepithelioma (6.6%). The most prevalent location for actinic lesions was the trunk (92.8%), being more prevalent on the ventral abdomen (82.1%). Actinic lesions were also present on head, neck and limbs. In 13/15 patients (86.6%), actinic lesions and at least one neoplasia location matched.Discussion: Actinic dermatitis tends to occurs in mid-aged to senile dogs because of the disease progressive and chronic behavior and owners delay to detect early clinical signs. In fact, actinic dermatitis was diagnosed at the average age of 7.6 years in the present study. The skin lesions were mostly located on light hair areas and were not observed on pigmented skin. The trunk (mainly the abdomen) had higher frequency of skin lesions compared to other anatomic areas, possibly because some dogs like to sunbathe at dorsal or lateral recumbency, some floor types can reflect sunlight, and some ventral abdomen are hairless. Ultraviolet radiation causes important local and systemic immunogenic changes. The impairment of the immune system and antigen recognition can influence cutaneous susceptibility to develop neoplasm. In conclusion, approximately 50% of the dogs with actinic dermatitis were associated with different skin neoplasm. The most prevalent was squamous cell carcinoma, mast cell tumor and hemangiosarcoma. Actinic lesions and neoplasm matched location in almost all patients with both conditions, however it was not possible to define if solar radiation had predisposed the occurrence of all observed neoplasms. Further studies are needed to prove the influence of ultraviolet radiation in the development of different cutaneous neoplasms