Abstract Background There are few birth cohort studies analyzing I g E sensitization in the tropics. Objectives We aimed to describe the evolution of total I g E and specific I g E responses to house‐dust mite ( HDM ) allergens and Ascaris in a birth cohort ( R isk F actors for A sthma and A llergy in the T ropics, FRAAT ), analyzing their relationships with wheezing. Methods Total and specific I g E were measured by I mmuno C ap in mothers and children at four different time points ( S 1– S 4) between 0 and 42 months. Parasite infection was evaluated by stool examination. Results Maternal total I g E (a OR : 2.43, 95% CI : 1.09–5.43; p = 0.03) and socio‐demographic factors were associated with high cord blood ( CB ) total I g E . High CB total I g E was positively associated with higher B lomia tropicalis and A scaris‐specific I g E values during lifetime, but protected from recurrent wheezing (a OR : 0.26, 95% CI : 0.08–0.88, p = 0.03). Prevalence rates of I g E sensitization were high; at around 3 yr old, they were 33.3, 18.6, and 26.5% for B . tropicalis , D ermatophagoides pteronyssinus, and A scaris, respectively. Indicators of unhygienic conditions were risk factors for HDM and A scaris sensitization in children. A weak statistical association between B . tropicalis‐ specific I g E and ever wheezing was found (a OR : 1.47 95% CI : 1.00–2.28, p = 0.05). Conclusions In a socioeconomically deprived community from the tropics, sensitization to HDM allergens was very frequent at early life, especially to B . tropicalis . In contrast to expected according to the hygiene hypothesis, unhygienic/poverty conditions were risk factors for allergen sensitization. High CB total I g E levels were a risk factor for allergen sensitization but protected from recurrent wheezing.