A 37-year female presents with multiple, linear, itchy wheals, with itching for 30 minutes at the site. The most probable diagnosis is:
High-Yield Explanation
Ans. a. Dermatographic urticaria (Ref; Roxburgh 17/e p71; Rooks 8/e p22.12; style="font-size: 1.04761904761905em; font-family: Times New Roman, Times, serif">article/}050294-overview)A 37-year-female presents with multiple, linear, itchy wheals, with itching for 30 minutes at the site. The most probable diagnosis is dermatographic urticaria.Dermatographic UrticariaThe term dermographism (or dermatographism) literally means writing on the skin.Firm stroking of the skin produces an initial red line (capillary dilatation), followed by an axon-reflex flare with broadening ery thema (arteriolar dilatation) and the formation of a linear wheal (transudation of fluid/edema); these events are collectively termed the triple response of Lewis.An exaggerated response to this constitutional whealing tendency is seen in approximately 2-5% of the population and is referred to as dermographismQ.Etiology:Exact mechanism remains uncertainSymptomatic dermographism is usually idiopathicEpidemiology:Dermographism is the MC of the physical urticariasQ and can occur with other forms of urticaria.More common in young adultsPeak incidence: 2nd to 3rd decadeClinical Features:Whealing usually develops within 5-10 minutes of stroking the skin and persists for 15-30 minutes.A short refractory period after clearance of the wheal has been reported.Symptomatic dermographism: Skin eruption is associated with itching, which is often most severe at night.Symptoms can be aggravated by heat (e.g., from a hot bath), minor pressure (eg, from scratching, from friction with clothes, or from rubbing with towels), exercise, stress, and emotionQ.Treatment:Recognition of the problem, avoidance of precipitating physical stimuli, reduction of stress and anxiety are important factors in medical care.In addition, scratching because of dry skin can be reduced through good skin care and the use of emollients.Pharmacologic therapy: HI antihistamines are the drugs of choiceQ.Omalizumab, a recombinant humanized monoclonal antibody against immunoglobulin E (IgE), has been successfully used in patients with physical urticaria, including symptomatic dermographism.