nokkosihottumaa

Nokkosihottuma (Finnish for urticaria or hives) is a dermatological condition characterized by the sudden appearance of itchy, raised wheals on the skin. Lesions are typically pale or red, transient—often resolving within hours at a given site—and may be accompanied by angioedema affecting the deeper dermis, mucous membranes or soft tissues.

The underlying mechanism involves mast cell activation and degranulation with release of histamine and other mediators, producing vasodilation and increased vascular permeability. Triggers include allergic reactions (foods, drugs, insect stings), infections, physical stimuli (pressure, cold, heat, sunlight), and internal diseases; many cases are idiopathic. Urticaria is classified as acute when lasting less than six weeks and chronic when symptoms persist longer; chronic forms are further divided into spontaneous and inducible subtypes.

Diagnosis is primarily clinical, based on history and appearance of lesions. Laboratory and imaging studies are reserved for suspected systemic causes or persistent disease. Provocation tests can identify physical triggers in inducible urticaria.

Management focuses on symptom control and avoidance of identified triggers. Second-generation, non-sedating H1 antihistamines are first-line therapy, with dose escalation if needed. Short courses of systemic corticosteroids may be used for severe flares. For chronic, treatment-refractory cases, biologic therapies such as anti-IgE agents and other immunomodulators can be considered under specialist care.

Prognosis is generally favorable for acute episodes; chronic urticaria can significantly affect quality of life and may remit spontaneously over months to years.