The Foot (1992) 2. 1 I7

Paul AS, Ohiorenoya B, Meadows TH. Subungal exostosis presenting as an ingrowing toenail The Foot (1991) 1, 125-126

We read with interest the case report on subungual exostosis by A. S. Paul et al in The Foot. The discussion of the report however, seems to have centred on the treatment of ingrown toenails, a subject on which publications are abundant. We felt that a few words on the history, aetiology and differential diagnosis of subungual exsostosis would not go amiss.

Subungual exostosis was probably first described by Dupuytren’ in 1847 and is sometimes called Dupuytren’s exostosis. Although it is usually described in the hallux, it has also been reported in other toes2s3 and in fingers. 3-6 This is a condition that predominantly affects the young7 (presenting age is usually between 10 and 25) and is twice as common in females as it is in males.3,8 There is often a history of trauma from which the condition dates, though the role of trauma in the pathogenesis of this con- dition has not been established. Dupuytren originally considered this condition to result from trauma, however there is evidence that it may be congenital in origin, and certainly the age group which is affected would support this hypothesis. The exostosis is usu- ally radiologically opaque and extends from the dor- sal side of the phalanx towards the nailbed. This may lead to elevation of the nail causing discomfort and pain. The swelling may provoke a fibrous reaction around it and the lesion may become verrucous and ulcerate. The diagnosis is not usually difficult unless complications have occurred. The differential diag- nosis includes subungual wart, malignant melanoma,

squamous cell carcinoma, pyogenic granuloma, and any other pathology leading to ulceration of the nailbed. Usually a good history, examination and X-ray will distinguish a subungual exostosis from other pathology.

In the case described by Paul et al, the infection and oedema in the nailbed may have disguised and made more difficult detecting the bony hard mass usually palpable in the nailbed and we would concur with the authors that a high index of suspicion is needed in order not to miss the correct diagnosis in these cases.

P. John FchS, SRCh S. K. Shami FRCS

The London Foot Hospital and School of Podiatric Medicine

References

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Dupuytren G. On the injuries and diseases of the bones, in Clark F (ed.): Publications of the Sydenham Society: London 1847; 20: 408-410. Paget J. Lectures on surgical pathology; delivered at the Royal College of Surgeons of England, vol 2. Philadelphia: Lindsay and Blakiston 1854: 461-2. Ippolito E, Falez F, Tudisco C et al. Subungual exostosis. Histological and clinical considerations on 30 cases. Ital J Orthop Traumatol 1987; 13: 81-87. Hutchinson J. Subungual exostosis of the great toe; excision with success. Lancet 1857; 2: 246-7. Matthewson M H. Subungual exostosis of the fingers. Are they really uncommon? Br J Dermatol 1978; 98: 187-189. Lowenthal K. Subungual exostosis on a forefinger. N.Y. State J Med 1964; 64: 2691-2695. Zimmerman E H. Subungual exostosis. Cutis 1977; 19: 185-187. Apfelberg D B, Draker D, Maser M R et al. Subungual osteochondroma: Differential diagnosis and treatment. Arch Dermatol 1979; 115: 472.

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