The majority of diseases resulting in feline skin fragility are acquired, but the pathogenesis of this rare syndrome is unknown. It is most commonly associated with such conditions as iatrogenic or naturally occurring hypercortisolism, diabetes mellitus, or extensive use of progestational compounds. Spontaneous hypercortisol-ism is responsible for 50% of cases. Iatrogenic hypercortisolism can cause skin fragility but only after prolonged exposure to topical/systemic steroids. In all cases, histology shows a thin epidermis and severely atrophic dermis. Dermal collagen fibers are severely attenuated and are pale-staining with a wispy appearance. The 4-year-old, spayed domestic shorthaired cat in this study presented with severe weight loss, anorexia, and occasional diarrhea. A 5 × 5 cm tear that occurred during transport to the veterinary hospital was present in the dorsal cervical region. Complete blood count showed an inflammatory leukogram with neutrophilia, increased segmented neutrophils, and lymphopenia. The cat was anemic and mildly thrombocytopenic. A diffusely enlarged and hypoechoic liver and spleen as well as a diffusely hypoechoic pancreas with hyperechoic peripancreatic fat were apparent with ultrasonography. The cat was euthanized due to its poor prognosis and clinical condition. Histoplasma organisms were identified within the dermis, liver, spleen, pancreas, lung, and bone marrow. Proposed mechanisms for the Histoplasma-associated skin fragility included the release of inflammatory mediators by infected and activated tissue macrophages or disturbed cutaneous blood flow secondary to severe vasculitis. Although this cat did not test positive for feline immunodeficiency virus or feline leukemia virus, an underlying immuno-deficiency could not be ruled out.
Commentary: This interesting case report provides an overview of cutaneous fragility syndrome in the cat and then attempts to provide a mechanism for the appearance of the syndrome in this particular case. Although the authors downplay the significance of the previously administered prednisone, I find it quite possible that this, along with cachexia secondary to systemic fungal disease, could have contributed to this cat’s skin fragility. It is worth noting that the condition was not reported prior to administration of prednisone, nor did this cat have the typical inflammatory granulomatous lesions associated with cutaneous histoplasmosis. While cause and effect cannot be proven, I feel that the prednisone treatment might be considered as a contributing factor.—Michael Schaer, DVM, Diplomate ACVIM & ACVECC
Disseminated histoplasmosis accompanied by cutaneous fragility in a cat. Tamulevicus AM, Harkin K, Janardhan K, Debey BM. JAAHA 47:e36-e41, 2011.