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Dermatographia
Î Patients with dermatographia (also known as dermatographism,
dermographia, and dermographism) promptly have a wheal-and-flare
response to pressure applied to the skin. Dermatographia can be
confirmed by stroking the skin with a firm object, such as a tongue
blade. Dermatographia is the most common form of physical urticaria
and reported to be present in 2%–5% of the general population,
although only a minority of patients have symptoms to a degree that
prompts medical attention. (B)
Exercise-Induced Urticaria And Anaphylaxis (EIAN)
Î Urticaria provoked by exercise can occur in patients with 2 conditions:
cholinergic urticaria or EIAn. (B)
Î There are 2 groups of patients with EIAn: one group can experience
anaphylaxis provoked by exercise, and a second group can experience
anaphylaxis with exercise temporally related to ingestion of food or
medication. (C)
Î Two subgroups of patients with food-dependent EIAn have been
described: one group can experience anaphylaxis when exercising in
temporal proximity to ingestion of any type of food, and another group
can experience anaphylaxis with exercise in conjunction with prior
ingestion of a specific food. (C)
Î It is important to distinguish EIAn from cholinergic urticaria. The
diagnosis of EIAn can be confirmed by means of exercise challenge in
a controlled environment, whereas cholinergic urticaria can be elicited
by means of both exercise challenge and passive heating. (C)
Î Management depends on determining whether the patient has EIAn or
cholinergic urticaria. If a food, drug, or another essential or modulating
factor is identified, this should be avoided in the peri-exercise period.
Patients with EIAn should carry injectable epinephrine, exercise with a
partner, and wear medical identification jewelry. (D)
Solar Urticaria
Î Patients with solar urticaria promptly (generally within 1–3 minutes)
experience urticaria with exposure of the skin to sunlight. (B)
Î The diagnosis of solar urticaria can be confirmed with phototesting to
various wavelengths of light. (B)
Vibratory Angioedema
Î Patients with vibratory angioedema experience pruritus and swelling
with exposure of the skin to a vibratory stimulus. This condition can be
familial. (B)
Î Vibratory angioedema can be confirmed by demonstrating an
exaggerated response after exposure of the skin to a vortex mixer. (B)
