Allergic conjunctivitis is the direct exposure of ocular mucosal surfaces to the environment that causes an immediate hypersensitivity reaction in which triggering antigens couple to reaginic antibodies (IgE) on the cell surface of mast cells and basophils, leading to the release of histamines that causes capillary dilation and increased permeability and thus conjunctival injection and swelling.
Nerve endings are also stimulated causing pain and itching.
Seasonal allergic conjunctivitis is the most common form in temperate climates. It usually occurs and recurs at a certain period of the year and subjectively more severe than perennial allergic conjunctivitis.
Perennial allergic conjunctivitis manifests and recurs throughout the year with no seasonal predilection. It is most common in tropical climates.
April 17 marks World Haemophilia Day, and this year’s theme is “Reaching Out – The First Step to Care”. Adjunct Assoc Prof Joyce Lam Ching Mei, head of the Haematology Laboratory and Blood Bank and senior consultant from the Paediatric Haematology/Oncology Service at KK Women’s and Children’s Hospital, Singapore, speaks to Elaine Soliven on the importance of recognizing and managing bleeding disorders in primary care.