Dermatography

Dermatography

Dermatography, also known as skin writing, is a condition where the skin becomes raised and inflamed when scratched or rubbed, often resulting in a temporary red mark or welt. This condition is a type of dermatographism, which is a form of physical urticaria.

Overview

Dermatography is characterized by the ability to "write" on the skin. When pressure is applied to the skin, it causes a localized reaction that results in a raised, red line or welt. This reaction is typically harmless and temporary, lasting from 30 minutes to a few hours.

Pathophysiology

The exact cause of dermatography is not well understood, but it is believed to involve the release of histamine from mast cells in the skin. This release is triggered by physical pressure or scratching, leading to the dilation of blood vessels and the characteristic swelling and redness.

Diagnosis

Diagnosis of dermatography is usually clinical and involves a simple test where the skin is lightly scratched with a blunt object. If a raised, red line appears within a few minutes, the test is considered positive for dermatography.

Management

While dermatography is generally benign and does not require treatment, symptoms can be managed with antihistamines to reduce the histamine response. Avoiding triggers such as tight clothing or excessive scratching can also help minimize symptoms.

Epidemiology

Dermatography is a common condition, affecting approximately 2-5% of the population. It can occur at any age but is more prevalent in young adults.

Also see

• Urticaria
• Histamine
• Mast cells
• Allergic reactions