Wealing and pruritic, long-lasting papules are a common nuisance from mosqu
ito bites. Antihistamines can be expected to decrease wealing, but their ef
fect on the delayed bite symptoms needs to be elucidated, We studied the ef
fect of ebastine in 28 mosquito-bite sensitive adult subjects exposed to Ae
des communis bites in the field. Ebastine 20 mg and placebo were given for
4 days in a cross-over fashion, and the size of the bite lesion and the int
ensity of pruritus (visual analogue scale) were measured at 15 min and 2, 6
and 24 h after the bites. Ebastine decreased significantly (p < 0.001) the
size of the bite lesion and pruritus at 15 min. Ebastine also had a signif
icant effect (p < 0.01) on pruritus at 2 and 24 h, and this effect was high
ly significant when the measurements at all 4 time points were pooled, Five
patients (18%) on ebastine, but none on placebo, experienced sedation (ns)
, The present field study shows that ebastine 20 mg given prophylactically
is effective against immediate mosquito bite symptoms, and that it also sig
nificantly decreases pruritus associated with the delayed bite papules.