Hives (urticaria) is one of the most sudden and bothersome skin reactions, affecting 20% of people at least once in life. It appears as raised red bumps with severe itching. The ClinicsJo Editorial Team reviews the causes and treatments.
What Are Hives?
Hives are a skin reaction featuring red or pink raised wheals surrounded by a red halo with intense itching. The cause: histamine release from skin mast cells in response to a trigger.
Types of Urticaria
1. Acute Urticaria
Lasts less than 6 weeks. Cause usually clear (food, drug, infection).
2. Chronic Urticaria
Lasts more than 6 weeks. In 50% of cases the cause is unclear (autoimmune).
3. Physical Urticaria
Triggered by a physical stimulus:
- Cholinergic: from heat and sweat.
- Cold urticaria: from cold.
- Dermographism: from skin scratching.
- Solar urticaria: from sunlight.
- Pressure urticaria: from tight clothing.
Common Causes
- Foods: peanuts, eggs, milk, fish, nuts, strawberries, tomatoes.
- Medications: penicillin, aspirin, NSAIDs.
- Infections: viral (cold), bacterial, parasitic.
- Insect stings.
- Chemicals: latex, dyes, perfumes.
- Psychological stress.
- Autoimmune diseases: lupus, thyroid disease.
- Hormonal changes.
Symptoms
- Raised red bumps of varying sizes (mm to cm).
- Severe itching.
- Appear and disappear within hours (each wheal lasts <24 hours).
- Migrate from place to place.
- May come with swelling of lips or eyelids (angioedema).
When Is It a Medical Emergency?
Go to a hospital ER immediately if you have:
- Difficulty breathing or swallowing.
- Swelling of the tongue or throat.
- Dizziness or fainting.
- Severe rapid pulse.
- Severe nausea or vomiting.
- Severe abdominal pain.
This may be anaphylaxis — requires immediate epinephrine injection.
Diagnosis
Clinical in acute cases. For chronic urticaria:
- Blood tests: CBC, ESR, CRP, TSH, ANA.
- Skin prick test.
- Specific IgE testing.
- Challenge testing in select cases.
- Skin biopsy in complex cases.
Treatment
1. Second-Generation Antihistamines
The foundation. Generally non-drowsy:
- Cetirizine (Zyrtec) 10 mg.
- Loratadine (Claritin) 10 mg.
- Fexofenadine (Telfast) 180 mg.
- Desloratadine (Aerius).
- Bilastine (Bilaxten).
In resistant cases, dose can be increased up to 4x under medical supervision.
2. First-Generation Antihistamines
- Diphenhydramine (Benadryl) — causes drowsiness, taken at night.
- Hydroxyzine (Atarax).
3. Oral Steroids
For severe cases for a short course (3–7 days). Avoid prolonged use.
4. Omalizumab (Xolair)
For chronic resistant urticaria. Monthly injection, very effective.
5. Other Options for Resistant Cases
- Cyclosporine.
- Leukotriene receptor antagonists (montelukast).
- H2 blockers (ranitidine).
Medical warning: If you have a history of anaphylaxis, always carry an EpiPen and ask your doctor for a written emergency action plan.
Preventing Flares
- Identify and avoid triggers (symptom diary).
- Avoid causative medications.
- Avoid heat and hot showers.
- Reduce stress.
- Avoid alcohol and spicy foods (stimulate histamine).
- Wear loose cotton clothing.
- Low-histamine diet in sensitive patients.
Urticaria and Pregnancy
May appear in pregnancy due to hormonal changes. Safe treatments:
- Cetirizine and loratadine (safe).
- Chlorpheniramine (first-gen, safe).
- Avoid steroids when possible.
If you have recurrent or chronic urticaria, book an appointment with a dermatologist or allergist on ClinicsJo.
