Most commonly found in middle-aged and elderly cats, it is characterized by pustules and crusting lesions common on the ears, nose plane, eye area, chin and paws.
The most common form of the disease in cats is lobular pemphigus, but many variants have been reported, including pemphigus vulgaris (involving a deeper dermis layer) and focal spinoseolytic dyskeratosis (more shallow, thought to be a version of Daryl's disease in humans).
This condition is caused by the production of "self" antigens against keratinocytes (skin cells), especially intercellular cementitum (glycocalyx) of the compound squamous epithelium. When autoantibodies bind to glycocalyx, a series of enzymatic reactions occur that disrupt adhesion between epidermal cells. Loss of intercellular cohesion leads to spintholysis and the formation of vesicles. Prematurely keratinized epidermal cells fall into the vesicles in the form of individual cells or cell rafts commonly referred to as spiny release cells. The release of inflammatory mediators is the chemotactic action of neutrophils, which rapidly migrate into vesicles. Clinically, these blisters appear as pustules that can easily rupture. The exudate in the blisters dries up quickly and is a typical source of crusts for these diseases.
These diseases do not seem to have a preference for reproduction. In one study, 60% of affected cats were domestic cats with short hairs.
Clinically, this disease leads to the formation of pustules and blisters in the hair and sparse hair areas. Lesions are usually symmetrical; nasal scabs with crusting around the eyes are highly suggestive of pemphigus. Intact pustules are rarely observed in animals and are most likely to appear in the inner auricles.
Affected cats are often depressed and anorgeuse and may have a pronounced peripheral lymphadenopathy, alopecia, paronychia, recurrent otitis externa and itching (about 80% of cases).
Clinical symptoms, characteristic spinous cells identified by lesion cytology, differentiation of other pustules to the exclusion of scleroderma, and compatible cutaneous histopathological examination.
Characterized by the presence of spinospersification in pathological specimens of cutaneous tissue. Diagnostic tests that should be performed include cytology, superficial skin scratches, and deep skin scratches. If these screening tests do not find any problems and there is clinical suspicion of feline pf, a biopsy should be collected for a histopathological examination of the skin and the culture submitted. It is recommended that the culture "prove" a sterile disease process. General laboratory tests are recommended, but are most useful when assessing the overall health of cats in order to plan long-term treatment with immunosuppressive drugs.
Cytology: careful collection of pus in intact pustules, or in the case of skin bulges leaving traces of corrosion, shows that spinous cells increase clinical suspicion of pf. Spinous release cells or free-floating rafts are often seen mixed with neutrophils and rarely eosinophils. However, the presence of spinosa cells is not unique to pf. Dermatophytosis and bacterial folliculitis can lead to spinosperm.
Histopathology of the skin: histopathology has the potential to provide the most valuable diagnostic information for the evaluation of biopsy lesions. Pustules are ideal for lesion submission, but scab lesions are the second best option. A cutaneous histopathologist will provide a description to identify typical patterns such as: pustular dermatitis, hyperplastic dermatitis, hyperkeratosis with focal keratosis, perivascular to interstitial neutrophils and eosinophil dermatitis, and perhaps keratinocyte apoptosis.
Differential diagnoses will include external parasites (cheyletiella spp, notedres spp, demodex spp, sarcoptes spp), ringworm, Malassezia, allergic, paraneoplastic diseases, and leishmaniasis.
Treatment requires immunosuppression and immunomodulation. Do not treat lobular pemphigus without diagnosis and exclusion of other differences.
Glucocorticoids are the most common initial treatment because they are effective anti-inflammatory and immunomodulators. There are many useful mechanisms of action in the treatment of autoimmune skin diseases, but the most significant role is the effect on humoral and cell-mediated immunity, phagocyte defense, inhibition of inflammatory mediators, and suppression of autoantibody levels.
Based on the experience of treating cats, glucocorticoid monotherapy achieves clinical remission in most cases. Prednisolone, prednisolone, triamcinolone, methylprednisolone and dexamethasone are the most widely used. According to an evaluation of some recent pharmacological data, cats should use prednisone instead of prednisone. Studies have shown that oral prednisone is not well absorbed and/or converted into the active form of prednisone in cats. Some prefer triamcinolone or dexamethasone over prednisone. Selected glucocorticoids should be administered in immunosuppressant doses until remission is reached (2-8 weeks) and gradually reduced to the lowest effective replacement daily dose for maintenance therapy. If side effects are not ideal, or if there is no significant improvement in re-evaluation at 2 and 4 weeks, alternative glucocorticoids should be selected, or NSAIDs should be added.
When glucocorticoid monotherapy is inadequate, chloramphenicol is most commonly used in cats. In addition to vomiting, diarrhea, and anorexia, bone marrow suppression must be monitored. Recommended platelet count cbc before and throughout treatment.
Cyclosporine is a nonsteroidal immunosuppressive drug that is sometimes prescribed. In autoimmune diseases, the clinical response is variable, usually to reduce the amount of glucocorticoids used. Side effects include vomiting, diarrhea, anorexia, weight loss, hypergingivity, hirsutism, and papillomatosis.
Prognosis is better, in cats, one study showed that 13% of cats were euthanized due to disease or treatment complications. Most cats require lifelong treatment to maintain remission. Regular monitoring of clinical symptoms, complete blood counts, and serum biochemical markers is important because immunosuppressive drugs can have side effects. Regular monitoring for adverse drug reactions, bacterial infections, dermatosis, and demodex mites is also required.