Dermatographism, also known as Dermographism urticaria, or urticaria factitia, is an urticarial eruption upon pressure or trauma to the skin. Urticarial skin reactions present as erythematous wheals in the dermis and can have innumerable causes. Dermatographism is the most common type of inducible/physical urticaria occurring in approximately 2% to 5% of the population. Dermatographism literally means "to write on the skin." Downward pressure on the skin produces linear erythematous wheals in the dermis in the shape of the external force that was applied. A small subset of those with dermatographism become symptomatic with pruritus, stinging, prickling sensations that can be severe and bothersome for the patient.
Although the exact cause of dermatographism is unknown, the release of histamine from mast cells is thought to play a role. Dermatographism has been seen in diabetics, hyperthyroid, hypothyroid, menopause, pregnancy, or drug-induced. Current hypotheses are described in pathophysiololgy section
Among the different types of urticaria, dermatographism is the most common. The condition frequently presents in young adults with the peak incidence in the second and third decades. There is no gender predilection, yet one study of pediatric patients showed a female predominance. There is no recognized racial predilection for dermatographism. One report cited a case of familial dermatographism.
A majority of patients with hypereosinophilic syndrome have dermatographism; these are associated with atopic children and an increased number of eosinophils in the blood. One-third of patients that experience traumatic life events along with psychological co-morbidities experience dermatographism. Furthermore, stressful events like pregnancy (commonly in the second trimester) and the onset of menopause have seen a higher incidence of the condition. Behcet disease, a condition marked by oral and genital ulcers, is another disease where dermatographism is a common integumentary finding.
Symptomatic dermatographism is thought to be generally idiopathic, but various explanations have been considered. The higher consensus revolves around Helicobacter pylori, antibiotics such as penicillin, bites, or scabies as the more common presentations to suggest this correlation. Lastly, congenital symptomatic dermatographism is the presenting sign in systemic mastocytosis.
No concluding mechanism explains why dermatographism occurs. Mechanical trauma activates vasoactive mediators released from mast cells secondary to antigen interaction to the bound IgE. This is thought to cause an exaggerated biological response known as the "triple response of Lewis." Initially, the capillaries become dilated, producing a superficial erythematous phase. Next, an axon-reflex flare and communication to sensory nerve fibers cause an expansion of erythema, secondary to arteriolar dilation. Lastly, the linear wheal is formed through fluid transudation. This entire response takes, on average, up to 5 minutes after an external stimulus stroking of the skin. The wheal can persist anywhere from 15 to 30 minutes, unlike the normal triple response of Lewis that subsides in under 10 minutes. Mediators such as histamine, leukotrienes, bradykinin, heparin, kallikrein, and peptides such as substance P are all considered to play a role in this process.
The histopathology of dermatographism demonstrates dermal edema with few perivascular mononuclear cells similar to the histology of acute urticaria.
Dermatographism lesions appear following mechanical trauma to the skin, most consistently stroking of the skin. A wheal forms and develops in approximately 5 to 10 minutes. The wheal will persist for about 15 to 30 minutes. The deeper the edema into the dermis, the larger the wheal will appear. In symptomatic dermatographism, pruritus accompanies the wheal. The pruritus worsens at night (thought to be related to pressure of the bedding and sheets contacting the skin) and with friction to the area from external stimuli, heat, stress, emotion, and exercise.
Dermatographism most commonly involves the trunk and extremities, and other body surfaces. The least common areas reported are the scalp and genital area, however symptomatic dermatographism has been correlated in the literature with dyspareunia and vulvodynia.
There are several rare subtypes of dermatographism:
Prevention and avoidance of precipitating factors such as physical stimuli and decreasing stressors are important factors in controlling dermatographism. Most patients are asymptomatic, and therapy should be restricted to patients that are symptomatic. Choice therapy includes treatment with H1 antihistamines such as cetirizine or loratadine. H2 antihistamines can be combined for a more complete therapy if H1 blockers are not sufficient to control the pruritus. Hydroxyzine, a sedating antihistamine and valid option, should be taken before sleep.
Omalizumab is under construction in research trials focusing on treating dermatographism with 72% efficacy on 150mg and 58% efficacy on 300mg. Notably, patients' Dermatology Life Quality Index (DLQI) scale improved by at least 4 points, showing a statistically significant clinical difference.
Light therapy has shown some efficacy in the treatment of dermatographism, yet most patients relapse within 2 to 3 months of completing therapy.
Adjunctive treatment with over the counter Vitamin C 1000 mg daily, is thought to help degrade histamine and increase removal, diminishing the triple response of Lewis.
If dermatographism is the leading differential, it is imperative that false dermatographism be ruled out, a condition that presents clinically similar to dermatographism but has a different underlying mechanism. False dermographism has several different forms including white, black and yellow. White dermatographism is secondary to allergic contact dermatitis and is prevalent in atopic individuals. Black dermatographism occurs after contact with metallic objects. Yellow dermatographism is due to bile deposits in the skin.
Another condition that presents similary to symptomatic dermatographism is latex allergy. This commonly is seen on the hands and genital region and will often be related to a history of physically contacting latex in gloves, rubber bands, balloons, toys, or contraceptive use.  Mastocytosis, a disorder caused by an increase in number of mast cells, can also present with pruritic red-brown pigmented lesions. Mastocytosis can be cutaneous or systemic depending on what area is infiltrated with mast cells. One sign of mastocytosis is called the "Darier sign" which is swelling, pruritus, and erythema in response to pressure applied to skin. Systemic mastocytosis is more common in adults, and symptoms are based primarily on the organ affected, such as the liver, spleen, bone marrow, or small intestine. Urticaria pigmentosa is the most common cutaneous mastocytosis in children, is rare and benign.
Dermatographism is a benign condition. In a minority of cases, pruritus can accompany the condition. In comparison to the other chronic urticarias, symptomatic dermatographism displays the most expedited clearance of the condition after 5 years (36%) and 10 years (51%).
Dermatographism can be unsettling in its laborious course without resolve. However, the condition is benign, and it is vital for patients to be aware of this. The treatment involved, antihistamines, can result in drowsiness; therefore, it is best to advise the patient to not take the medication before operating a vehicle.
Dermatographism is a benign, yet startling lesion to most patients and their parents. Thus, it is imperative to educate the patient and their parents properly on the risk factors associated with the onset of dermatographism to avoid such stressors. To properly educate, it is ideal to target the audience in a team-based approach.
|||Komarow HD,Arceo S,Young M,Nelson C,Metcalfe DD, Dissociation between history and challenge in patients with physical urticaria. The journal of allergy and clinical immunology. In practice. 2014 Nov-Dec [PubMed PMID: 25439372]|
|||Azkur D,Civelek E,Toyran M,Msrlolu ED,Erkoolu M,Kaya A,Vezir E,Gini T,Akan A,Kocaba CN, Clinical and etiologic evaluation of the children with chronic urticaria. Allergy and asthma proceedings. 2016 Nov [PubMed PMID: 27931300]|
|||Martorell A,Sanz J,Ortiz M,Julve N,Cerdá JC,Ferriols E,Alvarez V, Prevalence of dermographism in children. Journal of investigational allergology [PubMed PMID: 10923592]|
|||Jedele KB,Michels VV, Familial dermographism. American journal of medical genetics. 1991 May 1 [PubMed PMID: 2063925]|
|||Taşkapan O,Harmanyeri Y, Evaluation of patients with symptomatic dermographism. Journal of the European Academy of Dermatology and Venereology : JEADV. 2006 Jan [PubMed PMID: 16405609]|
|||Grimm V,Mempel M,Ring J,Abeck D, Congenital symptomatic dermographism as the first symptom of mastocytosis. The British journal of dermatology. 2000 Nov [PubMed PMID: 11069538]|
|||Lambiris A,Greaves MW, Dyspareunia and vulvodynia: unrecognised manifestations of symptomatic dermographism. Lancet (London, England). 1997 Jan 4 [PubMed PMID: 8988122]|
|||Maurer M,Schütz A,Weller K,Schoepke N,Peveling-Oberhag A,Staubach P,Müller S,Jakob T,Metz M, Omalizumab is effective in symptomatic dermographism-results of a randomized placebo-controlled trial. The Journal of allergy and clinical immunology. 2017 Sep [PubMed PMID: 28389391]|
|||Johnston CS,Martin LJ,Cai X, Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. Journal of the American College of Nutrition. 1992 Apr [PubMed PMID: 1578094]|
|||Golberg O,Johnston GA,Wilkinson M, Symptomatic dermographism mimicking latex allergy. Dermatitis : contact, atopic, occupational, drug. 2014 Mar-Apr [PubMed PMID: 24603512]|
|||Le M,Miedzybrodzki B,Olynych T,Chapdelaine H,Ben-Shoshan M, Natural history and treatment of cutaneous and systemic mastocytosis. Postgraduate medicine. 2017 Nov [PubMed PMID: 28770635]|
|||van der Valk PG,Moret G,Kiemeney LA, The natural history of chronic urticaria and angioedema in patients visiting a tertiary referral centre. The British journal of dermatology. 2002 Jan [PubMed PMID: 11841375]|