Peer-reviewed veterinary case report
Cat develops skin inflammation from methimazole treatment for thyroid
By Castro López, Jorge et al.·Published in Journal of feline medicine and surgery·2014·Department of Animal Medicine and Surgery, Spain·View original on PubMed →
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Original publication title: Pyogranulomatous mural folliculitis in a cat treated with methimazole.
- Species:
- cat
Plain-English summary
An 11-year-old spayed female domestic shorthair cat was brought in for excessive drinking, increased energy, and swollen thyroid glands. The vet suspected early hyperthyroidism and started treatment with methimazole, but after six months, the owner stopped the medication. A year later, the cat still showed symptoms, and when methimazole was given again, she developed skin issues like hair loss, redness, and crusty lesions. A skin biopsy revealed a condition called pyogranulomatous mural folliculitis, likely caused by an allergic reaction to the medication. After stopping methimazole, the cat's skin healed within 15 days.
People also search for: cat hyperthyroidism treatment · cat skin problems after medication · methimazole side effects in cats
Abstract
An 11-year-old spayed female domestic shorthair cat was presented for polydipsia, hyperactivity and bilateral thyroid gland enlargement. Total T4 (TT4) was in the upper interval range; therefore, an early hyperthyroidism was suspected. A treatment trial with methimazole was started, as the owner refused further tests. Six months later the owner stopped the treatment. One year later, clinical signs persisted and TT4 was still in the upper interval range. Methimazole was re-introduced but 48 h later the cat presented non-pruritic alopecia with erythema, scales and perilesional yellowish crusts. Pyogranulomatous mural folliculitis was diagnosed by histopatological examination of the skin biopsies. Methimazole was withdrawn and macroscopic lesions healed and disappeared histologically in 15 days. An idiosyncratic drug reaction to methimazole was suspected. To the best of our knowledge, this is the first report of feline pyogranulomatous mural folliculitis likely secondary to an adverse drug reaction to methimazole administration.
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Search related cases →Original publication on PubMed: https://pubmed.ncbi.nlm.nih.gov/24101746/