R.E. Meani, R. O’Keefe, R. Nixon, A.H. Chong
A 55-year-old female presented with multiple hyperkeratotic
verrucous nodules on her arms. Four weeks
earlier she had been pruning grevillea Robyn Gordon and
48 hours later she described onset of weeping and blistering
lesions over exposed sites with associated itch. She had
self-treated the areas with aloe vera gel and bathed with
pine tar solution. On examination one month after the
initial onset of rash there were multiple erythematous,
hyperkeratotic, verrucous nodules with visible excoriations
on her bilateral upper arms and forearms. Punch biopsies
were performed and histopathology revealed pseuodoepitheliomatous
hyperplasia (PEH), without granulomas.
Special stains and culture were negative for bacteria, atypical
mycobacteria and fungi. Subsequent patch testing
revealed a positive reaction to grevillea Robyn Gordon. The
patient was prescribed methylprednisolone aceponate ointment,
however she did not use this because of concerns
about topical corticosteroids. On review after two months
there was improvement of all lesions; however there was
evidence of residual linear hypertrophic scarring. This is
the first case of PEH secondary to contact dermatitis in the
literature. We postulate that this is an exaggerated response
to severe allergic contact dermatitis, contributed to by the
lack of topical treatment.