Ladakhi koilonychia

Introduction

A high prevalence of koilonychia has been reported in Ladakhis living in high altitude (3500 meter) by Anand and Harris[1] and Dolma et al.[2] Two groups of authors came to different conclusion as to the aetiology of the disability. They had also made observation on a small group of selected population. This prompted us to undertake a study of Ladakhit koilonychia in a bigger population with varied occupations

Material and Method

A total of 176 healthy highlander Ladakhis were examined for presence of koilonychia. Reading was taken for all of the 10 fingernails separately. Haemoglobin was also tested for all of them.

Results

The mean age of the subjects was 22.28 years (range 3- 58 years). 125 (71.02%) were males and 52 (28.98%) were females. A total of 83 (47.16%) of the subjects had koilonychia of varying degrees affecting one or more fingernails The frequency of involvement of various nails it as shown [Table - 1]. Mean haemoglobin levels it subjects with or without koilonychia was 14.17 gm and 14.12gm % respectively.

Relationship between age and frequency of koilonychia is as shown in Table II. Koilonychia was seen in 62 (49.60%) males and in 21 (41.34%) females.

Correlation between various occupations and prevalence of koilonychia is as shown in Table III. Miscellaneous group consisted of 3 housewives, 2 preschool children and one each of clerk, teacher, and shopkeeper, none of them being involved in physical labour. Most of the Ladakhi soldiers were also involved in farming during their leave.

Discussion

Hypochromic iron deficiency anaemia is the most well known cause of koilonychia.[3] In our study there was no significant difference in haemoglobin levels in those with or without koilonychia as was seen by Anand and Harris.[1] Annad and Harris[1] had also concluded that the tendency to koilonychia is a racial characteristic in Ladakhis. In contrast Dolma et al opined that koilonychia is much more common in women (23 out of 26 with koilonychia being women), it is seasonal, seen during summer months and is due to high silica content and alkalinity of the soil in which these women work. The prevalence of koilonychia seen by Dolma et al[2] was only 16.82% in contrast to 47.16% seen by us. The disability has been seen slightly more commonly in males by us, in contrast to the observations made by Dolma et al.[2] Koilonychia has been seen most commonly amongst soldiers, peasants and labourers i.e. those involved in hard manual labour and was less common in housewives, students and recruits. It is again most commonly seen during fourth and fifth decade i.e. after many years of exposure to chronic hypoxia superadded with mechanical trauma.

Nails of right thumb, index finger and middle finger followed by the same nails of left hand in that order are the most commonly affected nails, as is seen in iron deficiency anaemia.[1] This again suggests the role of trauma in right handed individuals. Chronic hypoxia of high altitude causes increased erythropoesis, depletion of iron stores and thinning of the nail plate.[4] Koilonychia develops because of depressed distal end of nail bed due to anoxia causing atrophy of the distal connective tissue.[3]The contention of Anand and Harris[1] that altitude did not seem to be factor is not true. The lowlanders serving in high altitude even for prolonged periods as mentioned visit their hometowns in lower altitudes at least twice in a year. This will reverse the physiological changes brought about by chronic hypoxia. Further the local population being Buddhist, are pure vegetarians and their diet is a poor source of iron. No green leafy vegetables are available for nine months in a year. The low iron content in their food is thus unable to meet the excess demand of increased erythropoesis in chronic hypoxic conditions. Hence this high prevalence of koilonychia in Ladakh should be considered a public health problem and adequate dietary iron supplementation should be started.