How is dermatographism managed?

Management of Dermatographism

The first-line treatment for dermatographism is non-sedating second-generation H1-antihistamines, which can be increased up to four times the standard dose for patients with inadequate response. 1

Understanding Dermatographism

Dermatographism (also called dermographism) is a common form of physical urticaria characterized by the development of linear wheals after scratching or friction on the skin, with or without angioedema. It has a prevalence of 2-5% in the general population, making it the most common type of physical urticaria 2. The condition occurs when mechanical stress on the skin triggers mast cell activation, leading to histamine release and formation of wheals along the stressed area 3.

Diagnosis

Diagnosis is primarily based on:

• Medical history
• Provocation test or dermatographic test (considered the gold standard) 3
• Assessment tools such as Urticaria Control Test (UCT), Chronic Urticaria Quality of Life questionnaire (CU-Q2oL), and Dermatology Life Quality Index (DLQI) can be used to evaluate disease control 3

Treatment Algorithm

First-Line Treatment

• Non-sedating second-generation H1-antihistamines (e.g., fexofenadine 180mg, cetirizine 10mg, loratadine 10mg) 1
  • These have a favorable safety profile with minimal sedation
  • Avoid sedating antihistamines, especially in elderly patients due to increased fall risk and cognitive impairment 1

Second-Line Treatment

• Increase antihistamine dose up to 4 times the standard dose for patients with inadequate response 1, 3
  • For example, fexofenadine can be increased up to 720mg daily

Third-Line Treatment

• Add leukotriene receptor antagonists (e.g., montelukast) as add-on therapy for resistant cases 1
• Consider omalizumab (300 mg every 4 weeks) for cases unresponsive to high-dose antihistamines 1
• Cyclosporine (4 mg/kg daily) for severe cases unresponsive to other treatments 1
• Narrowband UVB phototherapy for antihistamine-resistant cases 4, 5
  • Studies have shown significant improvement in both itching (mean reduction 52.3%) and whealing (mean reduction 71%) after 6 weeks of treatment 5
  • Treatment protocol: NB UVB phototherapy 3 times weekly for 6 weeks, starting at 50% of minimal erythema dose with 20% to 0% increments as tolerated 5

Additional Management Strategies

1. Trigger avoidance - Identify and avoid triggers that exacerbate symptoms 3
2. Regular assessment - Use validated tools to monitor treatment response 1
3. Step-down approach - Periodically reassess the need for continued therapy with an "as much as needed and as little as possible" approach 1

Prognosis

• More than 50% of patients with chronic urticaria will have resolution or improvement within one year 1
• However, patients with both wheals and angioedema tend to have a poorer prognosis, with over 50% still having active disease after 5 years 1
• The mean duration of symptomatic dermatographism has been reported as approximately 6¼ years 2

Special Considerations

• Symptoms are often worse in the evening (reported in 81% of patients) 2
• Stress can induce acute episodes (reported in 44% of patients) 2
• Quality of life is significantly impaired in 44% of patients 2
• A family history is reported in 14% of cases 2

Treatment Efficacy

• With H1-antihistamines, 49% of patients report marked improvement and 23% become symptom-free 2
• For antihistamine-resistant cases, narrowband UVB phototherapy can lead to subjective relief of pruritus and whealing, with objective reduction of whealing 5

Remember that dermatographism can significantly impact quality of life, and appropriate treatment can substantially improve patients' symptoms and daily functioning.