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.
Chronic hepatitis B virus (HBV) infection is a global problem. Chronic
HBV infection is probably the most common maternal infection encountered
in Hong Kong, China, and Southeast Asia. In Hong Kong, which is one of
the endemic areas, immunisation against HBV was first provided in 1983
to infants born to mothers who were screened positive for hepatitis B
surface antigen (HBsAg). Immunisation became widespread since November
1988, but HBsAg-positive mothers are still encountered frequently.1
Sudeta D Connolly, Sonali Nanayakkara,
01 Aug 2011
Anxiety disorders are one of the most common psychiatric disorders in children and adolescents, but they often go undetected or untreated. Identification and effective treatment of childhood anxiety disorders can decrease the negative impact of these disorders on academic and social functioning in youth and their persistence into adulthood. Because of the national shortage of child and adolescent psychiatrists in the US, paediatricians are increasingly called on to be front-line partners with child mental health professionals to coordinate care—with screening and early identification as well as with multimodal treatment of childhood anxiety disorders.
Dr Michael Lim, consultant of the Division of Paediatric Pulmonary and Sleep in National University Hospital, Singapore, shares his insights with Pearl Toh on diagnosing and managing paediatric asthma in the primary care setting.