Introduction
They are usually linked to a rapid release of histamine and can range from mild forms to more severe reactions that need urgent treatment.
Symptoms
- Hives (raised red patches that come and go)
- Intense itching
- Localised swelling (eyelids, lips, face)
- Widespread redness
- Burning sensation in the skin
- Rapid spread of the lesions
- Sometimes: feeling generally unwell or other associated signs
Causes
- Food allergies
- Drug allergies
- Insect stings or bites
- Contrast agents
- Latex
- Exposure to certain environmental allergens
- Physical exercise combined with an allergen (particular cases)
Diagnosis
- Detailed history (timing, trigger)
- Skin examination
- Looking for signs of severity
- Allergy tests at a later date (once symptoms have resolved)
- Ruling out other, non-allergic causes
Treatments
- Antihistamines as first-line treatment
- Short course of oral corticosteroids if needed
- Clinical monitoring
- Adrenaline auto-injector for severe reactions
- Hospital admission if there are systemic signs
Management
Identify the exact cause of the reaction
Prevent recurrences
Assess the risk of severe forms
Tailor preventive measures