Investigations
Investigations to consider
skin biopsy
Test
Result
Test
Skin biopsy can be used to confirm atypical or confusing cases.
Histopathological evaluation will demonstrate a superficial perivascular lymphohistiocytic infiltrate with focal spongiosis, focal parakeratosis in mounds, dyskeratotic keratinocytes, papillary dermal oedema, possible dermal eosinophils, and extravasated red blood cells.[7]
Result
typical histological features
antistreptolysin O titres
Test
Result
Test
To exclude streptococcal infection and/or guttate psoriasis.
Result
negative
potassium hydroxide (KOH) preparation microscopy or fungal culture
Test
Result
Test
To exclude fungal infection.
Result
negative
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