Severe halogen acne due to a trifluoromethylpyrazole derivative and its resistance to isotretinoin.

We report a case of severe chloracne, with systemic involvement, following occupational exposure to dihydrotrifluoromethylphenyl benzothiopyranopyrazolone, which, to our knowledge, has not been previously reported as a cause of chloracne. Aggressive drug treatment, including high-dose oral isotretinoin was of limited benefit in suppressing the disease activity.