Question:

A 6 years old boy was brought to us by his mother presenting with one year history of roughening of his finger nails. It started first on his right ring finger and now involved all ten fingers. Treated empirically as fungal infection with topical medication and a month's oral medication, the nails showed no improvement. The boy enjoyed good health other than this nail problem.

Physical examination showed pitting of all ten finger nails and a few pits on the nails of his right foot on close examination. While pitting was the feature of all the involved nails, some nails showed the features of ridging and grooves and the right ring finger surface had a sand paper-like quality.

Examination of other body parts showed no features of skin diseases. The oral mucosal surface was normal.

Answer: C. Twenty-nail dystrophy of childhood

The boy had twenty-nail dystrophy. It is an idiopathic disease of the nail commonly found in early childhood and sometimes in adults. All twenty nails will progressively develop dystrophy. Starting off with pitting, the nail dystrophy evolves into excessive ridging, grooves, striations, opaque discoloration, thinning and finally a rough sandpaper-like quality (trachyonychia).

Twenty-nail dystrophy is an idiopathic condition, although some congenital, familial and hereditary cases had been reported. Nail changes in other diseases like psoriasis, lichen planus, eczema, alopecia areata, onychomycosis and rarely dyskeratosis congenita resemble twenty-nail dystrophy. Hence patient presenting with features of this condition should be thoroughly examined for these conditions and followed-up for the subsequent development of them. Nail samples may be sent for fungal studies. If lichen planus is suspected a small punch biopsy of the nail matrix may be necessary. Twenty-nail dystrophy is a self-limiting condition. It usually resolves spontaneously in a few years' time without sequelae. Interventions with strong topical steroids are usually ineffective and intralesional steroids are very painful and will cause atrophy. If necessary manicuring and nail lacquer can improve the appearance; otherwise, in most patients, explanation, reassurance and yearly monitoring are all that is necessary.