Quaddeln

Quaddeln, in medical German terminology, are raised, well-defined skin lesions commonly known as wheals or hives. They result from localized edema in the dermis due to the release of mediators such as histamine from mast cells, leading to increased vascular permeability and fluid accumulation.

Clinically, a quaddel is typically pale in the center with a surrounding red flare, although appearance can vary. Sizes range from a few millimeters to several centimeters. Quaddeln are usually intensely itchy (pruritic) and transient, with individual lesions appearing and fading within minutes to hours. They can coalesce to form larger areas, and new lesions may appear while older ones disappear. In most cases they resolve without scarring within 24 hours, but recurrent or chronic urticaria can cause persistent symptoms.

Quaddeln occur in urticaria, which can be triggered by a wide range of factors. Common causes include infections, foods, medications, insect stings, and physical stimuli such as cold, heat, pressure, or sun exposure. Some cases are spontaneous (chronic spontaneous urticaria) or inducible by specific triggers (inducible urticarias). Angioedema may accompany wheals when deeper layers of the skin are involved, although the latter is a separate process.

Diagnosis is usually clinical. Skin prick or intradermal tests may be used to identify specific allergen triggers during suspected allergic urticaria. If wheals persist longer than 24 hours, are painful rather than itchy, or leave pigmentary changes, other conditions such as urticarial vasculitis should be considered.

Treatment focuses on symptom control and trigger avoidance. Second-generation antihistamines are first-line; dosing can be increased if needed. In severe cases, short courses of corticosteroids or other therapies (e.g., omalizumab) may be used. Education on avoiding triggers and recognizing signs of potential anaphylaxis is important.