Urticaria Pigmentosa and Mast Cell Involvement: What to Know

Medically reviewed by Deeptej Singh, MDMedically reviewed by Deeptej Singh, MD

Urticaria pigmentosa, also called maculopapular cutaneous mastocytosis, is a skin condition that causes spots on the skin and skin lesions. It stems from having too many mast cells in the skin, a type of white blood cell involved in the immune system.

Understanding how these symptoms manifest and their connection to mastocytosis can help identify the condition and seek appropriate treatment.

This article will help readers understand the relationship between urticaria pigmentosa and mast cells, urticaria pigmentosa symptoms, and treatments, as well as risk factors and management of the condition.

Urticaria Pigmentosa and Skin Effects

Urticaria pigmentosa is a skin condition often seen in systemic mastocytosis, in which too many mast cells in the skin cause itchy, brownish, patches of skin that can develop into hive-like bumps. Children may develop fluid-filled blisters. In darker skin tones, they may look purple or violet-colored.

Affected Body Parts

Urticaria pigmentosa can appear on any part of the body. It commonly affects the following areas:

• Face and neck

• Limbs (arms, legs)

• Scalp

• Trunk (chest, abdomen, back)

When these skin lesions begin in infancy or during childhood, the skin is usually the only affected organ.

Textures and Sensations

The lesions in urticaria pigmentosa appear as itchy, brownish patches of skin that may form hives when scratched. There be only a few spots or many spots covering a large area.

Rubbing an urticaria pigmentosa lesion can make the area turn red, swollen, and itchy. A blister may occur, a reaction known as Darier's sign, which helps diagnose the condition. In young children, these patches often blister when rubbed. If many patches are activated at once, the child might become itchy and irritable, though severe symptoms are rare.

Sometimes, mastocytosis in the skin can cause a massive histamine (chemical that can cause an allergic reaction) release. If this occurs, there may be additional symptoms, including:

• Headaches

• Flushing

• Low blood pressure (hypotension)

• Diarrhea

• Wheezing

• Vomiting

Symptom Onset and Duration

Urticaria pigmentosa typically begins in infancy and early childhood. Symptoms appear as reddish-brown spots or bumps on the skin that can itch and swell when irritated. These symptoms may persist for several years. This condition may also first manifest during adolescence or adulthood, presenting similarly with skin lesions that can be triggered by rubbing and may cause itching and discomfort.

Many infants and children tend to outgrow urticaria pigmentosa over time. No treatment is currently known to prevent their formation. The reddish-brown spots often diminish as the child ages but typically persist for several years.

Who Gets Urticaria Pigmentosa?

Urticaria pigmentosa happens when the body's mast cells release histamines in response to a perceived threat to the immune system. These histamines cause the characteristic swelling and itching of the skin in urticaria pigmentosa. Anything that triggers the release of histamines can cause someone to get urticaria pigmentosa.

Certain factors can cause urticaria pigmentosa, including:

• Age (more common in children, though it can also develop in adults)

• Rapid temperature changes

• Infections

• Drinking hot liquids
  

• Eating spicy foods

• Medications, particularly nonsteroidal anti-inflammatory drugs (NSAIDs) such as Advil (ibuprofen) and Aleve (naproxen), morphine, and some anesthesia medicines

• Stress and anxiety

• Exercise

• Rubbing the skin

Link Between Urticaria Pigmentosa and Mastocytosis

Urticaria pigmentosa is a type of cutaneous mastocytosis caused by the abnormal accumulation of mast cells in the skin.

Mastocytosis itself can be:

• Cutaneous: Primarily involving the skin

• Systemic: Affecting multiple organs
  

Systemic mastocytosis is a more serious form that affects multiple organs. While urticaria pigmentosa mostly affects the skin, in some cases, it can lead to systemic (body-wide) symptoms if mast cells spread to other parts of the body, like the bone marrow, brain, nerves, or digestive system. This progression means healthcare providers must watch for signs of the condition spreading beyond the skin.

Understanding this link helps healthcare providers monitor and treat urticaria pigmentosa and related mastocytosis.

Who to See for Urticaria Pigmentosa Diagnosis

Diagnosing urticaria pigmentosa typically involves consulting with specialists such as:

• Dermatologist: For skin examination and biopsy (removing a sample of skin for analysis in a lab)

• Allergist/immunologist: To assess mast cell activity and spread

• Hematologist: For further blood tests and bone marrow biopsies, if necessary

How to Soothe Urticaria Pigmentosa at Home

Before trying home remedies, talk to your healthcare provider to ensure you use an effective and safe treatment. Home remedies that may help manage symptoms and provide relief include:

• Apply a cool compress to the affected areas to reduce itching and swelling.

• Use moisturizers with no fragrances or perfumes.

• Identify and avoid triggers such as certain foods, stress, and temperature extremes.

• Take oatmeal baths to help alleviate itching and irritation.

• Use over-the-counter antihistamines to reduce itching and inflammation.

Prescribed Urticaria Pigmentosa Treatment

Prescription medications play a crucial role in managing urticaria pigmentosa symptoms.

Oral antihistamines are commonly prescribed to help alleviate itching and reduce the release of histamine from mast cells.

Mast cell stabilizers (like cromolyn sodium) or leukotriene inhibitors (such as montelukast) may be used to prevent mast cell activation and the subsequent release of inflammatory mediators.

Topical or oral corticosteroids are another treatment option for localized urticaria pigmentosa lesions that are particularly bothersome or resistant to other treatments. These medications help reduce inflammation and improve skin symptoms.

In cases where lesions are extensive or cause significant discomfort, phototherapy (light therapy) using ultraviolet A (UVA) or narrowband ultraviolet B (UVB) light may be recommended to help suppress mast cell activity in the skin.

Ttreatment for urticaria pigmentosa depends on the severity of symptoms and the patient's response to various therapies. Regular follow-up with a dermatologist or allergist-immunologist is essential to monitor the condition, adjust treatment as needed, and address any systemic symptoms that may develop over time.

Managing and Staying Ahead of Triggers

Triggers for urticaria pigmentosa are factors that can cause mast cells in the skin to release their contents, leading to symptoms such as itching, swelling, and redness of skin lesions. Common triggers include:

• Rubbing or scratching the skin lesions to provoke mast cell activation
  

• Exposure to heat or sudden temperature changes
  

• Spicy foods, alcohol, and foods containing histamine
  

• Venom from insect bites or stings
  

• Emotional stress and anxiety
  

• Medications such as NSAIDs and antibiotics
  

• Intense physical activity or exercise
  

• Exposure to certain chemicals or perfumes

Identifying and avoiding these triggers can help individuals with urticaria pigmentosa manage their symptoms more effectively and reduce the frequency of flare-ups.

Secondary Urticaria Pigmentosa Complications

Secondary complications of urticaria pigmentosa can arise due to the chronic inflammatory and allergic nature of the condition, particularly when mast cells accumulate and become activated in the skin. Some of these complications include:

Systemic Symptoms

While urticaria pigmentosa primarily affects the skin, some individuals may develop systemic mastocytosis, where mast cells accumulate in other organs such as the bone marrow, liver, or gastrointestinal tract. In very rare cases, it can turn into:

• Mast cell leukemia

• Mast cell sarcoma
  

Anaphylaxis

In severe cases, widespread activation of mast cells in response to triggers like insect stings, certain medications, or foods can lead to a systemic allergic reaction known as anaphylaxis. Anaphylaxis is a medical emergency requiring immediate treatment with epinephrine and urgent medical care.

Chronic Urticaria Pigmentosa Management

Living with urticaria pigmentosa involves regular check-ups with healthcare providers to monitor the condition and adjust treatments as needed. It may also help to connect with others via online support groups for support and advice.

Summary

Urticaria pigmentosa is a skin condition linked to mast cell dysfunction characterized by pigmented spots and itching. It can be associated with cutaneous or systemic mastocytosis and requires accurate diagnosis and management. By understanding the symptoms, triggers, and treatment options, individuals can better manage their condition or that of their child's.

Read the original article on Verywell Health.