Conjunctivitis allergic manifestation

It is frequently used in mild, local allergic reactions due to insect bites. It possesses sedative, antiemetic and anti-tussive properties and can be used in seasonal allergic rhinitis, allergic manifestations due to urticaria and allergic conjunctivitis of inhalant allergens. 

Although there are five types of hypersensitivity responses, two of these, types 1 and 1 play a significant role in the pathophysiology of allergic eye disease. The ocular manifestations include seasonal allergic conjunctivitis (SAC), giant papillary conjunctivitis (GPC), vernal keratoconjunctivitis (VKC), atopic keratoconjunctivitis, contact dermatitis, and urticaria. These are discussed in Chapter 27. 

The various types of allergic diseases that affect the conjimctiva include allergic conjimctivitis (hay fever conjunctivitis), GPC, VKC (spring catarrh), and AKC (eczematous conjunctivitis).The clinical manifestations of each of these allergic diseases vary in severity and duration, tanging from mild to severe. Loss of vision is a serious complication that may occur in AKC and VKC. 

Allergic conjunctivitis results from a type I immediate allergic reaction. The clinical manifestations reflect the immune response, and this response is discussed above and in Chapter 13. 

Type I reactions are IgE mediated and cause manifestations of allergic symptoms due to the release of immune mediators such as histamine or leukotrienes. These reactions typically occur within minutes of drug exposure and may manifest as generalized prurituS/ urticaria/ angioedema/ anaphylaxiS/ rhinitiS/ or conjunctivitis (21). Anaphylaxis can result from exposure to any antigen (e.g./ penicillin) and may be fatal in the absence of prompt medical intervention. 

Dexchlorpheniramine competitively antagonizes histamine Hi at receptor sites. It is indicated in treatment of perennial and seasonal allergic rhinitis vasomotor rhinitis allergic conjunctivitis mild, uncomplicated allergic skin manifestations of urticaria and angioedema amelioration of allergic reactions to blood or plasma dermographism and adjunctive anaphylactic therapy. 

It may be used for allergic conjunctivitis due to inhalant allergens (like pollens and dust), seasonal and perennial allergic rhinitis, and uncomplicated allergic skin manifestations of urticaria. 

It is frequently employed in the treatment of perennial and seasonal allergic rhinitis, allergic conjunctivitis due to inhalant allergens andfoods, simple allergic skim manifestations of urticaria and angioedema, dermographism and anaphylactic reactions as an adjunct to adrenaline. 

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