Dermatographic urticaria

Dermatographic urticaria
Classification and external resources
Dermatographic urticaria is sometimes called "skin writing".
ICD-10	L50.3
ICD-9	708.3
OMIM	125635
DiseasesDB	12736
eMedicine	derm/446

Dermatographic urticaria (also known as dermographism, dermatographism or "skin writing") is a skin disorder seen in 4–5% of the world's population and is one of the most common types of urticaria,^[1] in which the skin becomes raised and inflamed when stroked, scratched, rubbed, and sometimes even slapped.^[2] It is most common in teenagers and young adults, ages 15-30.^{[citation needed]}

Presentation

The symptoms are thought to be caused by mast cells in the surface of the skin releasing histamines without the presence of antigens, due to the presence of a weak membrane surrounding the mast cells. The histamines released cause the skin to swell in the affected areas.

This weak membrane easily and rapidly breaks down under physical pressure causing an allergic-like reaction, in general a red weal (welt) to appear on the skin. It can often be confused with an allergic reaction to the object causing a scratch, when in fact it is the act of being scratched that causes a weal to appear. These weals are a subset of urticaria (hives) that appear within minutes, in some cases accompanied with itching. The first outbreak of urticaria can lead to others on body parts not directly stimulated, scraped, or scratched. In a normal case, the swelling will reduce itself with no treatment within 15–30 minutes, but, in extreme cases, itchy red weals may last anywhere from a few hours to days.

Causes

The underlying cause of dermographism is not known, and can last for many years without relief. Five percent of chronic cases are never solved. Increased incidence has been observed following prolonged exposure to microwaves.^[3][4]The condition may subside and be effectively cured; however, it is often a life-long ailment. It is not a life-threatening disease and is not contagious.

Symptoms can be induced or worsened by periods of anxiety, physical stress, tight or abrasive clothing, watches, glasses, heat, cold,^[5] or anything that causes stress to the skin.

Treatment

Dermographism can be treated by substances which prevent histamine from causing the reaction. These may need to be given as a combination of H₁ antagonists, or possibly with an H₂-receptor antagonist such as cimetidine.^[6][7]

Not taking hot baths or showers may help if it is generalized (all over) and possibly for localized (in a specific area). If not taking hot showers helps, it may be a condition called shower eczema. If it affects mainly the head, it may be psoriasis. In rare cases, allergy tests may uncover substances the patient is allergic to. Using biodegradable or hypo-allergenic soaps and laundry supplies may help.

Using menthol mixed with aqueous cream is often an excellent temporary solution to help reduce irritation and itching in a localised area.

While cromoglycate, which prevents histamine from being released from mast cells, is used topically in rhinitis and asthma, it is not effective orally for treating chronic urticaria. Bug spray may also cause the reaction to the skin.^[8][9]

Frequent anecdotal evidence^{[citation needed]} suggests taking in small amounts of alcohol may help with the itching, or temporarily cause the inflammation/welts to subside.

Acupuncture and Chinese herbs have long been used to treat urticaria in the Asian world. Results of clinical trials of both acupuncture and Chinese herbs are inconclusive and are possibly a result of the placebo effect, as the trials did not involve a control group.^[10][11][12]

See also

• Triple response of Lewis
• List of cutaneous conditions

References

v t e Urticaria and erythema (L50–L54, 695, 708) Urticaria (acute/chronic) Allergic urticaria Urticarial allergic eruption Physical urticaria Cold urticaria Familial Primary cold contact urticaria Secondary cold contact urticaria Reflex cold urticaria Heat urticaria Localized heat contact urticaria Solar urticaria Dermatographic urticaria Vibratory angioedema Pressure urticaria Cholinergic urticaria Aquagenic urticaria Other urticaria Acquired C1 esterase inhibitor deficiency Adrenergic urticaria Exercise urticaria Galvanic urticaria Schnitzler syndrome Urticaria-like follicular mucinosis Angioedema Episodic angioedema with eosinophilia Hereditary angioedema Erythema Erythema multiforme/ drug eruption Erythema multiforme minor Erythema multiforme major (Stevens–Johnson syndrome, Toxic epidermal necrolysis) panniculitis (Erythema nodosum) Acute generalized exanthematous pustulosis Figurate erythema Erythema annulare centrifugum Erythema marginatum Erythema migrans Erythema gyratum repens Other erythema Necrolytic migratory erythema Erythema toxicum Erythroderma Palmar erythema Generalized erythema M: INT, SF, LCT anat/phys/devp noco (i/b/d/q/u/r/p/m/k/v/f)/cong/tumr (n/e/d), sysi/epon proc, drug (D2/3/4/5/8/11)