Summary about Disease
Pressure urticaria, also known as pressure hives or dermatographism, is a type of physical urticaria characterized by itchy welts that appear on the skin after pressure or friction. These welts can develop within minutes to hours of the pressure and typically resolve within a few hours, although some forms can persist for longer. It is generally not dangerous but can be uncomfortable and affect quality of life.
Symptoms
The primary symptom is the development of raised, itchy welts (hives) on the skin after pressure or friction. Other symptoms can include:
Redness of the skin.
Swelling.
Burning sensation.
Tenderness in the affected area.
Deep tissue swelling (angioedema) may occur in some cases, especially with delayed pressure urticaria.
Causes
The exact cause of pressure urticaria is not fully understood, but it is believed to involve the release of histamine and other chemicals from mast cells in the skin in response to pressure or friction. Potential triggers include:
Tight clothing.
Wearing a seatbelt.
Carrying heavy bags.
Walking or running.
Sitting for prolonged periods.
Hand tools or repetitive tasks causing pressure.
Medicine Used
The main medications used to manage pressure urticaria are:
Antihistamines: These are the first-line treatment and work by blocking the effects of histamine, reducing itching and swelling. Both H1 antihistamines (like cetirizine, loratadine, fexofenadine) and H2 antihistamines (like ranitidine) may be used.
Corticosteroids: In severe cases, oral corticosteroids (like prednisone) may be prescribed for short-term relief.
Leukotriene receptor antagonists: Medications like montelukast can be helpful for some individuals.
Omalizumab: This is a monoclonal antibody treatment that targets IgE and can be used in severe, refractory cases.
Is Communicable
No, pressure urticaria is not communicable or contagious. It is not caused by an infection and cannot be spread from person to person.
Precautions
Identify and avoid triggers that cause pressure on the skin.
Wear loose-fitting clothing.
Use padded straps for bags and backpacks.
Avoid repetitive pressure on the skin.
Apply cold compresses to relieve itching and swelling.
Avoid scratching the affected areas.
How long does an outbreak last?
The duration of an outbreak varies depending on the type of pressure urticaria:
Immediate pressure urticaria: Welts typically appear within minutes to an hour of pressure and resolve within a few hours.
Delayed pressure urticaria: Welts appear 4-6 hours (or even longer) after pressure and can last for 8-72 hours or even longer in some cases.
How is it diagnosed?
Diagnosis typically involves:
Physical examination: The doctor will examine the skin for characteristic welts.
History: A detailed account of symptoms, triggers, and duration.
Pressure testing: Applying pressure to the skin with a device (like a dermographometer or even a blunt object) to see if welts develop.
Ice cube test To rule out cold urticaria.
Blood tests: To rule out underlying conditions (rarely necessary but might be done to check for other causes of urticaria).
Timeline of Symptoms
The timeline varies depending on the type:
Immediate Pressure Urticaria:
Exposure: Pressure or friction applied to the skin.
Onset: Welts appear within minutes to an hour.
Peak: Symptoms intensify over the next hour.
Resolution: Welts fade and disappear within a few hours.
Delayed Pressure Urticaria:
Exposure: Pressure applied to the skin.
Latent Period: No symptoms for 4-6 hours or more.
Onset: Deep, painful welts and swelling appear.
Peak: Symptoms intensify over the next few hours.
Resolution: Welts fade over 8-72 hours or longer.
Important Considerations
Pressure urticaria can significantly impact quality of life due to discomfort and limitations on activities.
It is important to identify and avoid triggers as much as possible.
Treatment is aimed at managing symptoms and preventing outbreaks.
Consult a dermatologist or allergist for proper diagnosis and management, especially if symptoms are severe or persistent.
Angioedema is a potential complication and requires immediate medical attention.