Airborne salicaceae allergy in Ladakh

Abstract

A total of 65 patients who presented with eczema of the exposed parts of body in Ladakh at 3300 meters above sea level between July 97 to Sept 98 were studied. Forty-seven (72.3%) of the patients were in third and fourth decade (range 4-55 years). There were 34 (52.3%) males and 31 (47.7%) females belonging to varied occupations like farmers 14 (21.53%), housewives 12 (18.46%), soldiers/general duty 9 (13.84%), students 7 (10.76%), soldier/clerks 6 (9.23%), drivers 4 (6.15%) etc. In 49 (75.38%) the onset of illness was between April to July and 37 (75.5%) of them showed positive patch test reaction to either or both poplar and willow. Positive patch test reactions were also seen in 17 (77.27%) out of 22 in whom the disease was recurrent with periodicity once a year as compared to 3 (50%) out of 6 when the periodicity was more than once a year. Involvement of cubital and popliteal fossae and dorsum of the feet was rarely found. Patch test was found positive to willow (Salix sp.) alone in 22 (33.84%), to poplar (Populus sp.) alone in 24 (36.92%) and to both in 3(4.61%), that is an overall positivity in 49 (75.38%). Populus sp. and Salix sp. belong to the same family Salicaceae, however the cross-reactivity seen between the two has been found to be uncommon suggesting different chemical structure of their allergenic substance.