Proliferative, lymphocytic, infundibular mural folliculitis and dermatitis with prominent follicular apoptosis and parakeratotic casts in a Labrador retriever: Clinical, histopathological and dermoscopic features and co-morbidities

Proliferative, lymphocytic, infundibular mural folliculitis and dermatitis have been reported in six female Labrador retrievers from North America. This is the first report of the disease outside North America, describing the clinical and histopathological diagnosis and dermoscopic aspect of the verrucous plaques, treatment and co-morbidities in a female Labrador retriever dog.

Widespread, symmetric, noninflammatory alopecia associated with follicular dysplasia in the American red squirrel (Tamiasciurus hudsonicus)

This report describes a unique pattern of alopecia in 8 American red squirrels (Tamiasciurus hudsonicus) from 2013 to 2021. All animals were juveniles; 6 were female and 2 were male. Seven presented between September and November, and one presented in April. All squirrels had widespread, bilaterally symmetric, noninflammatory, well-demarcated alopecia involving the entire trunk and legs and normal hair on their muzzle and dorsal surfaces of their paws. Six months later, a normal hair coat had grown on 2 of the animals, which were littermates. Hair fully grew 2 months later in another animal. Histopathology of the alopecic skin was performed in 7 of 8 animals. The following changes were noted: bent and coiled hairs, perforating folliculitis, melanin clumping, and distortion of hair shafts. Based on features of follicular dysplasia and apparent seasonality, this condition has some similarities to canine seasonal flank alopecia. A genetic etiology is suspected.

Granulomatous mural folliculitis in 16 domestic goats: Infection with malignant catarrhal fever viruses and colocalization with ovine herpesvirus-2 using in situ hybridization

Granulomatous mural folliculitis (GMF) is an uncommon reaction pattern occasionally observed in nonadapted ruminant hosts infected with malignant catarrhal fever viruses. This report characterizes GMF and concurrent cutaneous lesions in 16 goats with crusting dermatitis using histochemistry including hematoxylin and eosin, periodic acid-Schiff, and Grocott's methenamine silver, and immunohistochemistry for CD3, CD20, ionized calcium binding adaptor molecule 1, and cytokeratin AE1/3. Infiltrates in all 16 GMF cases consisted of macrophages and fewer T lymphocytes, and variably included eosinophils, multinucleated histiocytic giant cells, and/or neutrophils. Formalin-fixed paraffin-embedded skin and fresh skin samples from caprine GMF cases were tested using pan-herpesvirus nested conventional polymerase chain reaction (PCR) and partial sequencing, ovine herpesvirus-2 (OvHV-2) real-time PCR, and OvHV-2 colorimetric in situ hybridization (ISH). Five of 16 goats with GMF (31%) were PCR positive for malignant catarrhal fever viruses, including caprine herpesvirus 3 in 1 goat and OvHV-2 in 4 goats. Three goats also had positive intranuclear OvHV-2 hybridization signal in follicular keratinocytes, among other cell types, localized to areas of GMF. Herpesviruses were not detected in the formalin-fixed paraffin-embedded skin of 9 goats without GMF. This case series describes relatively frequent detections of malignant catarrhal fever viruses in the skin of goats with GMF, including the first report of caprine herpesvirus 3, and localizes OvHV-2 infected follicular keratinocytes within areas of GMF.

Lymphocytic mural folliculitis and pancreatic carcinoma in a cat

A 9-year-old castrated domestic shorthair cat was presented with a 6 week history of progressive non-pruritic alopecia, polyphagia and weight loss. A diagnosis of lymphocytic mural folliculitis was made and the cat was treated with a combination of prednisolone and ciclosporin; this produced an improvement in the alopecia but no resolution. Sixteen months after the initial assessment and diagnosis, the cat was re-evaluated for intermittent vomiting and weight loss with normal appetite. On examination the dermatopathy was still evident and a mass involving the duodenum and pancreas was present, which was diagnosed as a pancreatic carcinoma. From this case it would appear that lymphocytic mural folliculitis might be an early dermatological manifestation of pancreatic neoplasia.

[A dog with an unusual case of alopecia; case report]

A dog with an unusual case of alopecia; case report We present a 6 years old English Bulldog with clinical and histological evidence of both cyclic flank alopecia and interface dermatitis, including folliculitis. A similar combination of these two dermatological diseases was described before in several Boxer dogs.

Prevalence of infiltrative lymphocytic mural folliculitis in equine inflammatory skin diseases

Infiltrative lymphocytic mural folliculitis (ILMF) is a histopathological reaction pattern reported to occur in a small number of equine inflammatory dermatoses. However, the prevalence of ILMF in a variety of equine dermatoses has not been reported. Skin biopsy specimens from 250 horses with inflammatory dermatoses and from 27 horses with physically healthy skin were therefore evaluated. ILMF was present in 82% of the diseased skin specimens examined. ILMF was not seen in physically healthy skin. It appears that ILMF is frequently seen in a wide variety of equine inflammatory dermatoses and therefore is of little diagnostic significance. However, ILMF is not seen in physically healthy equine skin and the presence of lymphocytes in equine hair follicle epithelium should therefore be considered abnormal.

Pulsed-field gel electrophoresis patterns and antimicrobial susceptibility phenotypes for coagulase-positive staphylococcal isolates from pustules and carriage sites in dogs with superficial bacterial folliculitis

OBJECTIVE

To determine whether coagulase-positive staphylococcal isolates that are genotypically the same strain obtained from pustules and carriage sites of individual dogs with superficial bacterial folliculitis have the same antimicrobial susceptibility phenotype.

ANIMALS

40 dogs with superficial bacterial folliculitis.

PROCEDURES

Samples were obtained from 3 pustules and 3 carriage sites (ie, anus, nonlesional axillary skin, and nasal mucosa) for bacterial culture, morphologic identification, Gram staining, catalase and coagulase testing, antimicrobial susceptibility testing, speciation, and pulsed-field gel electrophoresis (PFGE).

RESULTS

223 isolates from pustules and carriage sites were included. Seventeen susceptibility phenotypes were found among isolates. One hundred twenty-eight (100%) isolates from pustules and 95 (100%) isolates from carriage sites were susceptible to cephalothin; 128 (100%) isolates from pustules and 94 (98.9%) isolates from carriage sites were susceptible to amoxicillin-clavulanic acid; 114 (89.1%) isolates from pustules and 82 (86.3%) isolates from carriage sites were susceptible to erythromycin and lincomycin hydrochloride; and 103 (80.5%) isolates from pustules and 70 (73.7%) isolates from carriage sites were susceptible to trimethoprim-sulfamethoxazole. In 37 of 39 (94.9%) dogs, isolates with the same PFGE pattern from multiple pustules had the same susceptibility phenotype. In 21 of 33 (63.6%) dogs, isolates from multiple carriage sites with the same PFGE pattern had the same susceptibility phenotype.

CONCLUSIONS AND CLINICAL RELEVANCE

In dogs with superficial bacterial folliculitis, most coagulase-positive staphylococcal isolates from pustules that are genotypically the same strain will have the same susceptibility phenotype and treatment may be based on empiric antimicrobial selection or susceptibility testing of 1 lesional isolate.

Genotypic relatedness of staphylococcal strains isolated from pustules and carriage sites in dogs with superficial bacterial folliculitis

OBJECTIVE

To determine whether staphylococcal isolates cultured from pustules and carriage sites in dogs with superficial bacterial folliculitis were genotypically the same strain by use of pulsed-field gel electrophoresis (PFGE).

ANIMALS

40 dogs with superficial bacterial folliculitis.

PROCEDURES

Samples were obtained from 3 pustules and 3 carriage sites (anus, axillary skin, and nasal mucosa). Bacterial culture, morphologic identification, Gram staining, catalase and coagulase tests, speciation, and PFGE were performed.

RESULTS

Of 246 isolates, 203 were Staphylococcus intermedius, 5 were Staphylococcus aureus, 15 were Staphylococcusspp, and 22 were coagulase-negative staphylococcal isolates. No dog had an isolate with the same PFGE pattern as an isolate from another dog. Coagulase-positive isolates from multiple pustules and multiple carriage sites had the same PFGE pattern in 37 of 39 (94.9%) and 22 of 39 (56.4%) dogs, respectively. Coagulase-positive staphylococcal isolates from at least 1 pustule had the same PFGE pattern as an isolate from at least 1 carriage site in 34 of 36 (94.4%) dogs. Ninety-seven of 116 (83.6%) coagulase-positive staphylococcal isolates from pustules had the same PFGE pattern as an isolate from at least 1 carriage site. Sixty-nine of 91 (75.8%) coagulase-positive staphylococcal isolates from carriage sites had the same PFGE pattern as an isolate from at least 1 pustule.

CONCLUSIONS AND CLINICAL RELEVANCE

Coagulasepositive staphylococcal strains were heterogeneous among dogs with superficial bacterial folliculitis. In individual dogs, strains from multiple pustules were genotypically the same, and strains from pustules were genotypically the same as strains from carriage sites.

Three cases of immune-mediated adnexal skin disease treated with cyclosporin

Cyclosporin is currently considered a new and interesting drug in veterinary dermatology for the treatment of immune-mediated skin diseases, and a safe and effective alternative to immunosuppressive therapy with glucocorticoids. The authors report a case of granulomatous folliculitis and furunculosis and of sebaceous adenitis in two cats and a case of alopecia areata in a dog, successfully controlled with cyclosporin.

Alopecia areata with lymphocytic mural folliculitis affecting the isthmus in a thoroughbred mare

A 13-year-old, thoroughbred mare was presented with an 8-year history of multifocal, generalized, noninflammatory alopecia and a 3-month history of alopecia, erythema and scaling of the white star on the forehead and muzzle. Histopathological examination of biopsy samples from multiple sites on the body (mane, neck, shoulder, flank and gluteal region) showed a subtle lymphocytic inflammatory infiltrate affecting and surrounding the anagen hair bulbs, consistent with a diagnosis of alopecia areata. The biopsy sample from the star on the forehead showed atrophic hair follicles with perifollicular and mural mononuclear folliculitis affecting the isthmus. Immunohistochemical staining with a CD3 marker confirmed the T-lymphocytic origin of the inflammatory infiltrate in all the samples. The concurrent presence of lymphocytic infiltration at the bulbar and isthmic level of the hair follicles in the same horse is unusual. This finding may represent a variation of the histological appearance of alopecia areata.

Concurrent follicular dysplasia and interface dermatitis in Boxer dogs

Recurrent or persistent follicular dysplasia and interface dermatitis are described in nine Boxers. Data on age, sex, seasonality of alopecia and histopathological features of the follicular dysplasia in these nine Boxers are comparable with those described in previous reports. The interface dermatitis was characterized by multifocal annular crusted lesions confined to the areas of follicular dysplasia. The inflammatory lesions were neither pruritic nor painful and affected dogs were otherwise healthy. Histopathologically the clinically inflammatory lesions were characterized as an interface dermatitis. Immunohistochemical studies failed to demonstrate immunoglobulins or complement at the basement membrane zone or within blood vessel walls. In dogs with recurrent or persistent disease, the follicular dysplasia and interface dermatitis ran identical, concurrent courses of spontaneous remission and recurrence, or persistence, respectively. One dog with persistent disease was treated successfully with tetracycline and niacinamide for the interface dermatitis, and melatonin for the follicular dysplasia. Although the aetiopathogenesis of this newly described condition and the relationship between the two histological reaction patterns are not known, photoperiod and genetic predisposition appear to play a role.

Follicular dysplasia in five Weimaraners

This study evaluated the clinical and histopathological features and results of light and electron scanning microscopy assessments of follicular dysplasia in five Weimar Pointers. The data were compared with those obtained in three normal Weimaraners. In our study, this dermatosis affected young adults that showed progressive alopecia of the trunk (head and limbs were spared) associated with recurrent folliculitis/furunculosis. Exclusion of other dermatoses and the presence of histopathological lesions and hair shafts abnormalities seen in light and/or scanning electron microscopy similar to colour dilution alopecia led to the diagnosis of follicular dysplasia. The lesions we observed are the same as those described previously in colour dilution alopecia, but they were less pronounced in all our samples.

Mural folliculitis and alopecia caused by infection with goat-associated malignant catarrhal fever virus in two sika deer

Two sika deer from a zoo in Florida were examined because of chronic hair loss and skin lesions. No common causes of alopecia were identified in either deer. One deer was treated with prednisone, but the condition worsened when the dosage was decreased. Both deer were euthanatized after several months because of continued disease. The predominant histologic lesion in skin specimens was granulomatous mural folliculitis. Serologic testing and sequencing of fragments produced with a consensus polymerase chain reaction assay indicated that both deer were infected with caprine herpesvirus-2, a newly recognized member of the malignant catarrhal fever group of viruses. Disease in these deer was substantially different from that typically seen following infection with ovine herpesvirus-2, the sheep-associated malignant catarrhal fever virus. Findings in these deer establish the pathogenicity of caprine herpesvirus-2 in sika deer and illustrate the ability of this group of complex herpesviruses to cause a wide variety of clinical abnormalities in diverse species.

Degenerative mucinotic mural folliculitis in cats

A novel form of mural folliculitis is described in seven cats. Clinically, all cats exhibited generalized alopecia with scaling or crusting that was more pronounced over the head, neck, and shoulders. The face and muzzle of all cats was unusually thickened. Six of seven cats were progressively lethargic but did not demonstrate any other consistent systemic abnormalities. Histologically, there was severe mixed inflammation of the wall of the follicular isthmus in all cats, accompanied by some follicular destruction in five cats. Sebaceous glands were not affected. All cats had variable, but often striking, follicular mucin deposition, as well as epidermal hyperkeratosis and crusting. The cause of the severe mural folliculitis was not identified, and all cats responded poorly to immunomodulating therapy. Follicular mucinosis may be a nonspecific finding, likely reflective of the follicular lymphocytic milieu, and does not always herald follicular lymphoma.

Therapy of difficult cases of canine pyoderma with marbofloxacin: a report of 39 dogs

Thirty-nine dogs with severe and/or recurrent lesions of pyoderma were treated with marbofloxacin at an average dosage of 2.12 mg/kg bodyweight, once daily, for time periods varing from 10 to 213 days. Forty-seven strains of bacteria, isolated from 34 cultures, were tested for sensitivity to various antibiotics. At day 0, no resistance to marbofloxacin was found, but one refractory case, a strain of Staphylococcus intermedius resistant to marbofloxacin, was cultured at day 28. Thirty-three dogs (84.6 per cent) showed an excellent response (cure), one (2.6 per cent) a clear improvement and one (2.6 per cent) a smaller improvement, while the remaining four dogs showed no response after 11 to 60 days. Fifteen dogs (45.5 per cent) relapsed over the follow-up period of three to 191 days, but none of the dogs in the study exhibited any adverse effects.

Flea species from dogs and cats in northern Greece: environmental and clinical implications

Fleas were identified after being collected from 129 dogs and 38 cats of random breed, sex and age. All these animals, infested with fleas and admitted to the Clinic of Medicine of the Veterinary Faculty in Thessaloniki for routine procedures, were from different habitats and originated from various parts of northern Greece. Ctenocephalides canis was the most common species found on the dogs (71.3%). Conversely, its prevalence in the 14 cats was substantially lower (5.3%). Ctenocephalides felis was found on 97.4% of the cats and 40.3% of the dogs surveyed. Of the other flea species, with much lower prevalence, Pulex irritans (0.8%) and Xenopsylla cheopis (0.8%) were observed only on the dogs. Seventeen dogs (13.2%) and one cat (2.6%) had mixed infestations. Flea-associated dermatoses were observed in 26 dogs (20.2%) and four cats (10.5%). Flea-allergic dermatitis, with its typical manifestations, was seen in ten of the dogs (38.5%) with skin lesions. Three out of four flea-allergic cats presented miliary dermatitis and one symmetrical hypotrichosis.

Canine eosinophilic folliculitis and furunculosis in three cases

The historical, clinical and histopathological features of three dogs with eosinophilic folliculitis and furunculosis are described. The disease was characterised by the rapid development of pruritic, papular, pustular and ulcerative lesions on the dorsum of the muzzle. Skin lesions were confined to the face in two cases. The third dog had more generalised pustular lesions. Skin biopsy specimens showed marked eosinophil infiltration particularly centred on pilosebaceous units. Dermal collagen necrosis was evident in two cases. Similar facial lesions have previously been described as 'nasal pyoderma'. The three dogs failed to respond to initial antibacterial therapy but showed a rapid clinical response when prednisolone was given orally at doses ranging from 1 to 2.2 mg/kg, in addition to the antibacterial therapy, suggesting that glucocorticoids are indicated for the treatment of eosinophilic folliculitis and furunculosis. The aetiology of the disease was not determined.

Comparative histopathology of pemphigus foliaceus and superficial folliculitis in the dog

A comparative histopathologic study of 50 cases of pemphigus foliaceus and 47 cases of superficial folliculitis in the dog was undertaken to identify those histopathologic features important in differentiating these diseases. All cases were diagnosed by the Surgical Pathology Service of the Laboratory of Pathology of the University of Pennsylvania, School of Veterinary Medicine, between January 1986 and March 1991. These cases were followed clinically to determine the accuracy of the initial histopathologic diagnosis. Data were analyzed by Fisher's exact test for discrete data and the Mann-Whitney U-test for continuous data. A probability of < 0.05 was considered statistically significant. The following breeds were affected with pemphigus foliaceus: Akita, Brittany Spaniel, Chow Chow, Collie, Dachshund, Doberman Pinscher, English Cocker Spaniel, English Setter, Golden Retriever, Siberian Husky, Laborador Retriever, Miniature Schnauzer, Old English Sheepdog, Scottish Terrier, Chinese Shar Pei, Spitz, Shetland Sheep Dog, Weimeraner, and West Highland White Terrier. An increased risk of developing pemphigus foliaceus was noted in the Akita (OR = 37.8), English Springer Spaniel (OR = 20.7), Chow Chow (OR = 12.3), Chinese Shar Pei (OR = 7.9), and Collie (OR = 3.9). Pemphigus foliaceus had a higher average density of acantholytic cells (226 +/- 22.9) than superficial folliculitis (11.8 +/- 4.6), and acantholytic cells were 183 times more likely to be present in pemphigus foliaceus. The presence of rafts of acantholytic cells occurred in pemphigus foliaceus (23/50) more often than superficial folliculitis (1/47). Recornification and reformation of pustules were, respectively, 13.4 and 3.6 times more likely to occur in pemphigus foliaceus.(ABSTRACT TRUNCATED AT 250 WORDS)

Dermatologic disorders of Chinese Shar Peis: 58 cases (1981-1989)

A retrospective study on the skin diseases of Chinese Shar Peis was conducted over a 9-year period. Skin disease was found in 58 (49.2%) of the 118 dogs studied. Folliculitis was the most common clinical finding (43 of 58 dogs). In 6 dogs, there was no apparent reason for the folliculitis; however, it was secondary to allergic dermatitis, demodicosis, IgA deficiency, or hypothyroidism in the other dogs. Approximately 20% of the dogs had more than one of these disorders. Serum IgA concentration was measured in 7 dogs and was low in all 7.

Corynebacterium folliculitis in a horse

A 7-year-old Thoroughbred was examined for evaluation of mildly pruritic multiple skin lesions that had progressed from nodules to alopecia and crusts. Folliculitis caused by Corynebacterium pseudotuberculosis was diagnosed by bacterial culture. Oral treatment with a trimethoprimsulfadiazine paste resulted in resolution of all lesions, with normal hair regrowth.

Sterile eosinophilic pustulosis in dog and man: comparative aspects

Sterile eosinophilic pustulosis is a rare dermatosis of dogs and humans. The clinicopathologic aspects of the disorder are similar in both species. In both the disease is characterized by a moderately generalized, pruritic, sterile, follicular and nonfollicular papulopustular dermatitis. Blood and tissue eosinophilia are usually present. Response to systemic glucocorticoids is better in dogs, probably because of the larger doses that can be used. The disorder is chronic and recurrent in both species.

[Bacterial skin infections in the dog (author's transl)]

The most common bacterial skin conditions in dogs are reviewed in the present paper. An introductory part on the pathogenesis of pyoderma and some universal morphological dermatological concepts is followed by a systematic study of superficial and deep forms of pyoderma. In addition to the bacterial diagnosis, the results of bacteriological examination of fifty-three dogs with pyoderma submitted to the University Clinic of small animal medicine are reported. Moreover, a guide to the institution of adequate therapy is suggested.