Persistent itching of the eyelids and scalp

A woman in her mid 50s presented with a month long history of persistent itching in both eyelids. She had received a diagnosis of blepharitis and conjunctivitis, and treatment with topical antibiotic and corticosteroid therapy, but she had seen no improvement in her symptoms. On slit lamp examination, the right eye conjunctiva was erythematous, and numerous lice and nits (eggs) were seen attached to the base and shaft of the eyelashes (fig 1). Lice and nits were also visible on the forehead and right temporal scalp, under operating microscopy. On light microscopy, the parasites were seen to be wingless, crab-like lice with a distinct head, a pair of slim weak anterior legs, and two pairs of thick strong posterior legs. The nits firmly adhered to the eyelashes. Examination of the eyebrows, …