Relevance of skin-prick test and immunoglobulin E estimation in pigeon-exposure asthma patients

Background
Pigeon exposure is common in India due to its cultural and religious practice. Hypersensitivity to pigeon allergen is well known as pigeon breeder disease. Limited data also show that pigeon allergen was associated with increased asthma. The aim of this study is to evaluate skin-prick test (SPT) and immunoglobulin E (IgE) levels in pigeon-exposed asthmatics.


Patients and methods
It is a prospective observational study with 200 asthma patients as per Global Initiative for Asthma guidelines. As per the history of exposure to pigeons, patients were divided into two groups: exposed and nonexposed asthmatics. All patients underwent SPT against CAA with pigeon allergen and measurements of serum IgE. The result was compared between two groups.


Results
Out of 200 patients with mean age of 29.83±9.92 years, 108 had pigeon exposure. The SPT against CAA sensitivity was positive in 74% exposed and 63% nonexposed groups. While SPT against pigeon allergen was positive in 17 (15.7%) in exposed patients. The mean total IgE was higher in exposed asthmatics but not significant (538.75±248.5 and 510.2±220.1 IU/ml, P=0.0078). The mean specific IgE against pigeon dropping and feather was significantly higher in exposed asthmatics (0.4513±1.01 and 0.1957±0.179 KUA/l, P=0.003; 0.3644±0.329 and 0.1176±0.116 KUA/l, P=0.000).


Conclusion
The asthmatic patients with exposure to pigeons had higher SPT against pigeon allergen and higher total and specific IgE against pigeon antigens. This may be one of the reasons for higher asthma in urban cities.