The rule of three rang true for a trio of unlucky siblings in Mexico when doctors found a rare fungal source for their near-identical head lesions.

A concerned father brought in the three children — two boys and a girl, aged between four and six — who presented with pruritic lesions, or kerions, on their scalps that were 3cm in diameter and had been present for at least a month.

The pseudo-alopecic plaques on the occipital and parietal regions of the scalp had “a dirty appearance”, exhibiting erythema, oedema and “honey-like crusts”, the doctors wrote in Cureus.

All three kids had palpable bilateral cervical lymphadenopathy and ecto–endothrix parasitisation in the hair shaft.