1. Military Hospital, Luanda, Angola
2. Department of Immunoallergology, Hospital da Luz, Lisbon
3. Department of Mathematics, Faculty of Sciences, University of Beira Interior, Covilhã
4. Department of Allergy & Clinical Immunology, Cova da Beira Hospital, Covilhã, Centro de Investigação em Ciências da Saúde, University of Beira Interior, Covilhã, Portugal