Urticaria

197 Urticaria



Instruction


Look at the skin of this patient, who has recurrent lesions.



Salient features



History




• Determine physical causes that could have precipitated this response: cold urticaria, dermatographism (Fig. 197.1), pressure, sunlight, exercise, hot shower


• Drug history: aspirin, NSAIDs, morphine, codeine, penicillin, sulphonamides


• Whether any foods precipitate the rash such as strawberries, seafood, nuts, chocolate


• Blood products causing these lesions.


• Wasp or bee stings


• Viral infections and febrile illnesses


• Know whether the patient has recurrent angioedema


• Obtain a history of atopy.


image

Fig. 197.1 Urticaria.



Examination




• Wheals that are smooth, oedematous, pin or red, and surrounded by a bright red flare. Clearing of the central area may leave an annular pattern.


• Associated scratch marks, indicating the wheals are itchy.


Proceed as follows:



• Tell the examiner that you would like to exclude infections (hepatitis, chronic sinusitis) and connective tissue disorders.



Diagnosis


This patient has wheals (lesion) caused by chronic urticaria and dermatographism (aetiology), complicated by severe itching (functional status). Tell the examiner that you would like to exclude urticarial vasculitis before making a firm diagnosis.


Notes



• SLE and Sjögren’s sydrome may present with urticarial lesions, which are usually urticarial vasculitis.


• Chronic urticaria is the occurrence of daily or almost daily widespread itchy wheals for at least six weeks (N Engl J Med 1995;332:1767–72). This includes urticarial vaculitis and physical urticaria.

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Dec 4, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Urticaria

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