What is Dermatographism?
Dermatographism, sometimes referred to as Dermographism urticaria or urticaria factitia, is a skin condition that causes a rash when the skin is pressed or injured. This rash appears as red, swollen marks in the skin’s deeper layers and can have many different causes. Dermatographism is the most common type of physically induced rash, affecting 2-5% of people across the globe. If you press down on the skin, you’ll see red, swelled-up lines forming in the shape of the force applied, which is why it’s called dermatographism – it literally means “writing on the skin.” Some people with dermatographism have symptoms like itching, stinging, or prickling sensations, which can be uncomfortable.
What Causes Dermatographism?
Doctors aren’t completely sure what causes dermatographism, a skin condition where lightly scratching your skin causes it to become raised and red. They believe it may be related to the release of a substance called histamine from certain cells in your body known as mast cells. Dermatographism has been observed in people with a variety of conditions like diabetes, an overactive or underactive thyroid, menopause, and pregnancy. It can also be linked to certain medications.
Risk Factors and Frequency for Dermatographism
Dermatographism is a type of skin condition known as urticaria, and it’s the most common form of it. It usually starts showing up in young adults, particularly during their twenties and thirties. While anyone of any race can get dermatographism, studies have found that it tends to affect more women than men.
- Those with atopic conditions and a higher number of a certain blood cell type—eosinophils—are more associated with dermatographism.
- About one-third of people who go through traumatic experiences or struggle with psychological issues also experience dermatographism.
- Stressful situations such as pregnancy, especially in the second trimester, and the start of menopause have been linked to a higher occurrence of this condition.
- People with Behcet disease, a condition that causes oral and genital sores, often have dermatographism as well.
The exact cause of symptomatic dermatographism is not known, but several factors have been linked to it, including infection with a bacteria called Helicobacter pylori, the use of antibiotics like penicillin, insect bites, and a parasitic skin infection called scabies. If congenital symptomatic dermatographism is present, it could be a sign of a disease called systemic mastocytosis.
Signs and Symptoms of Dermatographism
Dermatographism is a skin condition where the skin reacts to physical pressure or rubbing, leading to raised welts or hives. These welts usually appear about 5 to 10 minutes after the skin is rubbed, and they can last from 15 to 30 minutes. The more pressure that’s applied, the larger the welt would be. In more severe cases, these welts are accompanied by itching, which tends to worsen at night and can be triggered by heat, stress, emotion, and exercise.
The trunk and limbs are the most commonly affected areas, but dermatographism can appear on other parts of the body as well. However, it rarely appears on the scalp and genital area. This condition has been associated with painful sexual intercourse and chronic pain in the vulva in some reported cases.
There are various less common types of dermatographism including:
- Red Dermatographism (small red pinpoint hives mainly on the trunk)
- Follicular Dermatographism (individual urticarial spots)
- Cholinergic Dermatographism (large red lines with pinpoint hives, akin to a related condition called cholinergic urticaria)
- Delayed Dermatographism (painful hives that show up 3 to 8 hours after the initial injury and can last up to 48 hours)
- Cold-precipitated (triggered by cold)
- Exercise-induced (triggered by physical activity)
- Familial (runs in families)
Treatment Options for Dermatographism
To manage dermatographism, it’s important to avoid things that trigger it like physical stimuli and stress. Treatment is usually only necessary for patients who show symptoms. The go-to treatment is usually H1 antihistamines like cetirizine or loratadine. If these don’t fully control the itchy skin, H2 antihistamines can be added. Hydroxyzine, another type of antihistamine that can make you drowsy, is another option and can be taken before sleep.
There’s research being done on a treatment called Omalizumab. The studies show it’s effective for about 72% of people on a 150mg dose and 58% of people on a 300mg dose. A measure called the Dermatology Life Quality Index, which gauges how skin conditions affect a person’s life, improved significantly for patients in these trials.
Light therapy can also work, but most patients experience a return of their symptoms within 2 to 3 months after finishing their treatment.
A daily vitamin C supplement (1000mg) which you can get over the counter might help. It’s thought to help break down histamine, a chemical your body produces that causes the symptoms of dermatographism.
What else can Dermatographism be?
When trying to diagnose dermatographism (a skin condition causing noticeable welts or hives after the skin is lightly scratched or rubbed), doctors need to consider other conditions with similar symptoms. One of these is “false dermatographism,” which is similar in appearance, but caused by different underlying factors. False dermatographism can come in several types—white, black, and yellow. White dermatographism is typically caused by allergic reactions, particularly in those with existing skin conditions. Black dermatographism is usually seen after contact with metal objects, and yellow dermatographism results from deposits of bile, a digestive fluid, in the skin.
Other conditions with similar symptoms to dermatographism include a latex allergy, characterized by rashes often on the hands or genital area. It’s usually linked to physical contact with items made from latex, like gloves, rubber bands, balloons, toys, or contraceptives.
Another possibility is a condition called mastocytosis, which is due to an increase in mast cells (a type of immune cell). This can cause itchy, red-brown spots on the skin. Mastocytosis can occur on the skin or throughout the body, depending on where the mast cells increase. A common sign of mastocytosis is the “Darier sign,” which is swelling, itching, and redness when pressure is applied to the skin. In adults, mastocytosis is often systemic, meaning it affects various organs, like the liver, spleen, bone marrow, or small intestine. In children, the most common type is called urticaria pigmentosa, which is rare and not harmful.
What to expect with Dermatographism
Dermatographism is a harmless condition. In some cases, it can come with itchiness. When compared to other long-term hives conditions, symptomatic dermatographism tends to clear up faster after 5 years (36% of cases) and 10 years (51% of cases).
Possible Complications When Diagnosed with Dermatographism
Having Dermatographism doesn’t cause any direct problems. Nevertheless, if you’re using antihistamines that make you drowsy as a treatment, you should be careful when doing certain activities. This includes things like driving or using machinery.
Preventing Dermatographism
Dermatographism, a skin condition, may be frustrating because it often takes a long time to clear up. However, it’s important to know that it’s not a harmful condition. Treatment usually involves taking antihistamines, which can make you feel sleepy. As such, it’s recommended not to take this medication before driving a car.