High altitude koilonychia.

Objective: To study the incidence of koilonychia in the residents of high altitude.
Methods: Nails of all the patients attending the Medical Outpatient Department (MOPD) of a multispeciality medical camp at Kaza in Himalayas (height 12,500 feet above sea level) were looked for the presence of koilonychia and were included for the study. Those residing below 10,000 feet were excluded from the study. A detailed history was taken and a thorough physical examination was made in each. Routine laboratory investigations were undertaken. Serum ferritin levels were estimated in seven.
Results: Koilonychia was present in 6.99% of the patients (67 out of the 986). There were 29 males and 37 females within the age range of 37 to 78 years. Sixty four were high landers since generations and three were high landers from 2nd generation onward. All were right handed. Koilonychia was in the nails of both upper and lower limbs in 14, in the nails of upper limbs in 49 and in the nails of lower limbs in 18. In the upper limbs it was in all the fingers in 42, in thumb, index and middle fingers of right hand in 12 and of left hand in nine. In the lower limbs it was bilateral in the first three toes in nine. Chronic obstructive pulmonary disease was in 29, ulcer like dyspepsia in 24, osteoarthritis of knee in 17, hypertension in 14, pulmonary tuberculosis in eight, anxiety neurosis in five, pneumoconiosis in two and squamous cell carcinoma of lung in one. The haemoglobin in all was normal and serum ferritin level of the seven patients estimated was also normal.
Conclusions: Koilonychia at high altitude is present in 6.99%. It is due to retardation of nail plate growth and is more common in upper limbs.