Furry animals are a common source of allergens, but little is known about the allergenicity of scaly animals. To the best of our knowledge only 2 cases of respiratory allergy to iguana have been published in the medical literature1,2. In contrast to our patient the 2 reported cases presented rhinoconjunctivitis together with asthma.
Two additional cases have been reported in Spain but not published so far in indexed journ als. However, with the gain in popularity of exotic pets, such as iguanas or other reptiles, the incidence of allergy to these animals may increase and allergists should be aware of their potential as “new” indoor allergens.
We present a case of asthma and eosinophilia with onset in a non-atopic adult woman. The routine allergological evaluation was negative, but the patient presented an elevated total IgE, had pets at home, and when carefully questioned reported worsening of her asthma at home, improvement away from home, and data suggesting the potential involvement of the iguana in her symptoms (Figure 4).
Indeed, we have confirmed that the patient presented an IgE mediated asthma due to the green iguana she had at home. After the removal of the iguana the patient has been followed for 15 weeks and we have been able to demonstrate a clinical improvement corroborated by the normal PEF monitoring, together with a reduction in bronchial inflammation (decrease in sputum ECP) and a parallel decrease in bronchial hyperreactivity 3 (increase of PC20 methacholine). Without a full allergological evaluation this patient would have been diagnosed as having an intrinsic asthma and would have only received anti-asthmatic medication with a probably poor control of her asthma 4.
This case report stresses the importance of the correct etiologic diagnosis in asthma, since the identification and subsequent avoidance of the culprit allergen is a key prognostic factor that can modify the disease progression – persistent inflammation, airway remodelling – and the prognosis of the patient.