Ulceration of upper lip with no antecedent pruritus.
Cat is otherwise healthy.
Excessive grooming observed.
Clinical signs
Focal area of ulceration with a raised pink/white proliferative margin and a depressed brown/yellow center .
Unilateral or bilateral on upper lip.
Non-pruritic.
Painless.
Peripheral lymphadenopathy.
Oral lesions .
Lesions in other areas of the skin especially eosinophilic plaque .
Diagnostic investigation Bacteriology
Carefully performed cultures are negative.
Histopathology
Non-diagnostic. Shows a hyperplastic, ulcerative dermatitis with perivascular to interstitial inflammation, with neutrophils, plasma cells and mononuclear cells.
Hematology
Eosinophilia is rare.
Other
Flea comb to look for fleas or flea feces .
Skin scrape for other ectoparasites .
Intradermal skin test for atopy .
Food trial for food sensitivity .
Confirmation of diagnosis Discriminatory Diagnostic features
Oral antibiotics 3-6 weeks therapy may give partial or total remission of some cases.
Systemic glucocorticoids if no response seen to oral antibiotics.
Injectable methylprednisolone , 4-5 mg/kg IM, max 20 mg in a dose q2 weeks until a beneficial response is seen (typically 2-3 treatments). Once in remission then q2 months or discontinue if possible.
Oral glucocorticoids: High dose prednisolone 5 mg/kg q24h, once in remission 2 mg/kg q48h. Methylprednisolone 4 mg/kg q24h. Triamcinolone 0.5-0.75 mg/kg q24h. If lesions resolve, taper to lowest possible alternate day dosage.(May be possible to taper triamcinolone to twice weekly).
Megestrol acetate has glucocorticoid effect.
Immunomodulating drugs if no response to glucocorticoids. But beware serious side effects, eg bone marrow suppression.
Chlorambucil 0.1-0.2 mg/kg q24h reducing to q48h if beneficial response.
Levamisole 2.2 mg/kg q48h PO.
Thiabendazole 5 mg/kg q48h PO. Megestrol acetate is not recommended because of potential side effects. Use only in cases unresponsive to any other therapies. Dose: 2.5-5 mg/cat q48h tapering to 2.5-5 mg q7-14days.
Surgery
Sharp surgical excision - may leave deformities.
Cryosurgery: Poor results.
Radiation therapy.
Laser therapy.
Monitoring
Clinical signs.
If on long-term glucocorticoid therapy then 6-12 monthly assessment of hematology, blood biochemistry and urinalysis to look for side-effects.
But beware serious side effects, eg bone marrow suppression.
