Wheals – Causes, Symptoms and Treatment

What Are Wheals?

Wheals (also called hives or urticarial lesions) are transient, raised skin lesions caused by a localized accumulation of fluid in the superficial dermis. They appear as pale or reddish elevated patches, often surrounded by a red flare (erythema). Wheals can appear singly or in large numbers across the skin and are typically accompanied by intense itching.

Causes

Wheals develop when certain triggers cause mast cells in the skin to release histamine and other inflammatory mediators. This leads to local vasodilation and the leakage of fluid into surrounding tissue.

• Allergic reactions: to foods (e.g., nuts, shellfish), medications, or insect stings
• Physical stimuli: pressure, cold, heat, or sunlight (physical urticaria)
• Infections: viral or bacterial illnesses can trigger wheals
• Autoimmune conditions: in chronic spontaneous urticaria, the immune system targets the body´s own structures
• Idiopathic causes: in many cases, no specific trigger is identified

Symptoms

Wheals are easily recognized by their characteristic appearance:

• Raised, pale or reddish skin elevations
• Intense itching, sometimes accompanied by a burning sensation
• Transient nature: individual wheals usually disappear within 24 hours
• Variable size: from a few millimeters to several centimeters in diameter
• Possible accompanying symptoms: swelling (angioedema) of the lips, eyelids, or other areas

Diagnosis

Diagnosis is typically based on a clinical examination and a thorough medical history to identify possible triggers. Additional diagnostic steps may include:

• Allergy testing: skin prick tests or specific IgE blood tests to identify allergens
• Laboratory tests: complete blood count, inflammatory markers, thyroid function tests
• Provocation tests: for physical urticaria, e.g., cold stimulation tests

Treatment

Treatment of wheals depends on the underlying cause and severity of symptoms.

Pharmacological Treatment

• Antihistamines: first-line therapy; they block histamine receptors and relieve itching and redness (e.g., cetirizine, loratadine)
• Corticosteroids: used short-term for severe or persistent reactions
• Biologics: e.g., omalizumab for chronic urticaria unresponsive to antihistamines
• Epinephrine (adrenaline): emergency treatment in cases of anaphylaxis involving wheals

General Measures

• Avoiding known triggers
• Cool compresses to relieve itching
• Use of gentle, fragrance-free skin care products

When to See a Doctor

Wheals accompanied by difficulty breathing, swallowing difficulties, severe swelling, or circulatory collapse represent a medical emergency and require immediate medical attention. Persistent or recurring wheals without a clear cause should also be evaluated by a healthcare professional.

References

1. Zuberbier T. et al. - The EAACI/GA2LEN/EDF/WAO guideline for the definition, classification, diagnosis and management of urticaria. Allergy, 2022.
2. Magerl M. et al. - Urticaria and Angioedema. Deutsches Ärzteblatt, 2021.
3. World Allergy Organization (WAO) - Urticaria: A Review of the Current State. WAO Journal, 2020.