In symptomatic dermographism, disease activity is affected by eating and exercise
Published: December 16, 2022
Symptomatic dermographism (SD) is characterized by the appearance of wheals on the skin accompanied by itch and/or a burning sensation after scratching, rubbing, and/or friction. SD is the most common subtype of chronic inducible urticaria (CIndU). The diagnosis of SD is made by provocation testing, i.e. scratching of the skin with a blunt object (a tongue blade, for example, or a dermographometer such as FricTest®). Provocation testing with a dermographometer has the added benefit of allowing for the assessment of disease activity, by measuring the threshold of trigger strength in individual patients. How this threshold and disease activity are affected by eating or exercise was previously unknown.
In the current study published in The Journal of Allergy and Clinical Immunology: In Practice, Ertaş and coworkers tested 75 patients with SD for the impact of eating, exercising, or both on trigger thresholds and disease activity. First, they tested the patients with FricTest® before eating and after eating, and they looked for changes in SD disease activity and checked if any patients had increased disease activity after eating. Then, they did the same with exercise, testing patients with FricTest® before and after exercising, to see if any of them showed a change in disease activity linked to exercising. Finally, they looked for the combined effect of eating and exercising on SD disease activity.
Two thirds of SD patients had increased disease activity after eating, and one in ten had active SD only after eating. Exercise, on the other hand, often improved SD disease activity, in eight of ten patients. Also, exercising protected patients from worsening after eating in half of cases. These results are the first to show that eating and exercise affect SD disease activity. That eating can worsen SD and that exercising can improve it has many implications, for SD patients and for physicians who treat them. Patients who experience worsening of their SD after eating may be able to prevent this by exercising before or after eating. Physicians who test patients for their disease activity by provocation testing should advise their patients to not eat or exercise before the test, so that true disease activity and thresholds are assessed.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.