A man has recurrent uicaria following exercise and coming out in sun. Diagnosis is:
Ans. a. Cholinergic uicaria Cholinergic uicaria develops due to acetyl choline liberated from post ganglionic cholinergic enervated sweat glands under the influence of any stimuli which induces sweating by increasing core body temperatureQ. Precipitating factors are exercise/physical exeiondeg, emotion upsetdeg, exposure to sun/heatdeg and hot bath/foodQ Physical Uicaria Dermographism Solar uicaria Cold uicaria Cholinergic uicaria Dermographism This is exaggerated triple response of lewisQ. In some patients of uicaria mark easily when their skin is scratched or rubbed with a blunt objectQ It is not influenced by an atopic diathesis a.nd has a duration of less than 5 years. Uicaria Vasculitis Transientdeg but rarely it may stay for days rather than hours and leave a brownish stain. It is due to involvement of small vesselsQ Uicaria pigmentosa/Mastocytosis There are excess mast cellsdeg in many tissues but mainly manifest in the skinQ Multiple pink or red brown macule or papuleQ develops over the trunk and limbs. Lesions may be intensely itchy and patient may experience discomfo and erythema when bathing. Rubbing or heating may result in its swelling and a red halo- Darrier's signQ Sometimes alcohol, opioids or other drugs may cause histamine release from visceral mast cell deposits Cholinergic Uicaria Uicaria develops due to acetyl choline liberated from post ganglionic cholinergic enervated sweat glands under the influence of any stimuli which induces sweating by increasing core body temperatureQ. Characteristic feature is small size pruritic wheals surrounded by large erythemaQ Precipitating Factors Exercise/Physical exeionQ Emotion upsetQ Exposure to sun/heatQ Hot bath/foodQ
Cholinergic uicaria
Atopic reaction
Photo dermatitis
Chronic idiopathic uicaria