GUnica! and Experimental Dermatology (1977) 2, 115.

Occupational koilonychia

RODNEY DAWBER Department of Dermatology, The Slade Hospital, Headington, Oxford 0x3 7JH

Accepted for publication 2-] July 1976

Koilonychia is most commonly seen in iron deficiency anaemia, peripheral arterial disease (Samman, 1972), as a temporary normal phenomenon in childhood and as an isolated hereditary abnormality (Hellier, 1950). Over a 2-year period three patients, all car mechanics, were seen with koilonychia of fingernails (Fig. i) who felt that this was due to constant immersion in oils. This report outlines the results of clinical, occupational and laboratory studies of this association.

Figure i. Occupational koilonychia, showing a typical severely affected thumbnail.

Investigations Eight major motor vehicle service centres were visited and the nails of 94 car mechanics examined. 128 manual workers who had little or no contact with oils were examined as controls. Results Five of the car mechanics had koilonychia (53",,) whilst none of the controls were affected. Table i shows the fingernails affected in the 8 subjects so far seen with koilonychia. The

Il6

R. Dawber Table i. Affected nails in eight mechanics with koilonychia (all right-handed) Fingernail

Right

Left

Thumb Index Middle Ring Little

8 8 8 8 6

8 8 7

4 2

thumbs and index fingernails were most severely affected and the koilonychia was less pronounced towards the little fingers which were less frequently affected, particularly on the nondominant side. Keratin amino-acid analysis carried out on nail clippings from three affected individuals and five normal controls showed no abnormality; in particular cystine was not significantly decreased, i.e. Koilonychia-mean cystine 478%; mean of controls 433% (expressed as a percentage of amino-acid nitrogen extracted excluding ammonia).

Discussion A search of the medical literature has revealed only a single previous case report of industrial koilonychia of this type (Passano & Botbol, 1945). The results of this study suggest that occupational koiionychia is not rare, affected individuals are simply not normally seeking medical attention. The first patient seen attended because his sister, a nurse, suggested to him the possibility of anaemia, whilst the second and third affected individuals were referred by works medical personnel aware of the author's interest. A previous report suggested that koilonychia due to iron-deficiency was caused by a deficiency of sulphur-containing cystine in nail keratin (Jalili & Al-Kassab, 1959). One cannot postulate this mechanism here since cystine was normal. The frequency distribution of koilonychia shown in Table i suggests that the fingers most typically and severely involved are those undertaking the greatest amount of work. It seems likely that oils in some way soften the nails which then become re-shaped by actions such as screwing. References HELLIER, F . F . (1950) Hereditary koilonychia. British Journal of Dermatology, 62, 213-215. JALILI, M.A. & AL-KASSAB, S. (1959) Koilonychia and cystine content of nails. Lancet, ii, 108-110. PASSANO, J. & BOTBOL, A. (1945) Un caso clinico de koilonychia. Revista Argentina de Dermatosifilogia,

March issue, 38. (1972) The Nails in Disease, 2nd edn, p. 104. Heinemann Medical Books Ltd, London.

SAMMAN, P . D .

Occupational koilonychia.

GUnica! and Experimental Dermatology (1977) 2, 115. Occupational koilonychia RODNEY DAWBER Department of Dermatology, The Slade Hospital, Headington...
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