What Is Urticaria?
A skin disease made up of a wheal, and flare reaction is known as urticaria. An area of redness surrounds the localized wheal in urticaria, and it is typically itchy. In the case of hives, a local increase of the permeability of the capillaries and small venules results in transient, erythematous, or edematous swelling of the dermis or subcutaneous tissues. Cutaneous hives may last for 30 minutes to 24 hours. If the wheals or hives persist for more than 24 hours in an individual and have joint pain and bruising, then it should be considered urticarial vasculitis. Systemic symptoms like rhinitis, difficulty in breathing, the sensation of heaviness in the chest, wheezing, and abdominal pain may accompany the skin lesions and are indications for urgent treatment to avoid the complication of laryngeal edema. Potential mediators of urticaria include histamine, prostaglandin D2, platelet-activating factor, bradykinin, etc.
How Is Urticaria Classified?
Urticaria can be broadly classified into acute and chronic.
1. Acute urticaria is usually IgE mediated. The duration is less than 6 weeks. It occurs due to various foods, drugs, and infections.
2. Chronic urticaria lesions continue to appear in an individual at least twice a week for more than 6 weeks due to inflamed blood vessels, physical and autoimmune causes, etc.
What Are the Provoking Causes of Urticaria?
The provoking causes of urticaria are: Physical factors account for 20% of cases. They are stroking (dermographism), constant pressure like prolonged sitting on a chair or tight belt, vibration like kitchen grinder or blender, cholinergic like emotion, exercise, cold and aquagenic such as urticaria after swimming. Medications such as Aspirin, Penicillin, Codeine, Morphine, ACE inhibitors (Envas - Enalapril), and NSAIDs (nonsteroidal anti-inflammatory drugs) like Brufen (Ibuprofen), Combiflam (combination of Ibuprofen and Paracetamol) provokes urticaria. Foods and food additives can cause urticaria. For example, foods such as shellfish, eggs, nuts, strawberries, etc., and additives like tartrazine, azo dyes, hydroxyl benzoates, etc. Inhalants such as grass pollens, animal danders, tobacco smoke, and house dust. The contact urticaria syndrome is mainly due to latex, caterpillars, animals, and plants. Arthropod assaults like insect bites are the most important cause of papular urticaria. Infections of bacteria, viral, candidal, and protozoal can also be the cause. General medical disorders such as hypo or hyperthyroidism, lymphoma, polycythemia, lupus erythematosus, pruritic urticarial papules, and plaques of pregnancy. Psychogenic causes and genetic causes like hereditary angioedema.
What Are the Symptoms of Urticaria?
The following are the clinical features of urticaria:
- Raised skin lesions occurring anywhere on the body.
- Lesions appear in clusters.
- The lesions cause itchiness all over the body.
- Raised skin lesions appear to be red, pink, or skin-colored.
- The color may fade when a person starts to press the middle of the lesion.
- Usually, the lesions do not stay longer than 24 hours, but new lesions may form.
- The size of the lesion may range from pinprick to several inches. Urticaria does not always appear as blisters.
These lesions may also occur as:
- Tiny dots.
- Spots.
- Raised thin lines.
Depending on the cause, the time taken by the lesions to appear might differ. In people with contact urticaria, the skin may react to latex or any other irritants. The skin starts to react within 10 to 60 minutes and may last up to a day. Urticaria occurs within an hour in people with food allergies, but reactions to additives and food colorings may appear after 12 to 24 hours. However, bodily reactions to a drug start to begin at once or later, even years after using the medication. In the case of chronic hives, the symptoms may persist for several days, months, or years.
Urticaria may develop on different parts of the body such as legs, arms, face, and trunk.
- On legs - Papular urticaria develops in response to an insect bite, which commonly occurs in children. It can develop all over the body, but the legs are the most common part that gets affected.
- On the face - Urticaria on the face is due to an allergy or sensitivity reaction. It mostly causes swelling of the lips and may spread and affect the throat, mouth, and airways, making it difficult to breathe. Breathing difficulty is an emergency situation that needs immediate treatment.
How Is Urticaria Diagnosed?
A detailed history gives a better yield regarding the cause than a battery of investigations in all patients. Provocative tests for physical urticarias like ice cube test for cold urticaria, exercise test for cholinergic urticaria, stroking for dermographism, etc., are definitive for diagnosis. In selected patients, the need will arise to check the following blood tests. Complete blood count. ESR (erythrocyte sedimentation rate). Urine analysis. Stool examination for ova and cyst. Blood chemistry profile. ANA (antinuclear antibody). Hepatitis B and C antigens and antibodies. Thyroid antibodies. Cryoglobulins. CH 50. Hereditary C1 esterase deficiency. Plasma and erythrocyte protoporphyrins (solar urticaria). Skin biopsy in urticarial vasculitis and IgE and IgE receptor antibody assay.
How Is Urticaria Treated??
The treatment options for urticaria are listed below.
- H1 antihistamine is the initial line of treatment. During the daytime, Loratadine, Levocetirizine, and Fexofenadine are given, and at night, Hydroxyzine or Cyproheptadine is used because of the sedation.
- Corticosteroids are useful in the case of acute urticaria for a short duration. It is rarely used in chronic urticaria.
- Mast cell stabilizers like Ketotifen 1 to 2 mg daily or Cromolyn sodium inhaler and Montelukast (leukotriene receptor antagonist) are useful in case of recalcitrant disease.
- In the case of autoimmune urticaria, Cyclosporine 2 to 2.5 mg/kg daily for two to three months or IVIG (intravenous immunoglobulin) or plasmapheresis is the treatment.
- For angioedema, the treatment is the same as above, along with Epinephrine 0.5 to 1 mg IM (intramuscular) in case of acute episodes and repeat every 10 to 15 minutes till remission or Ephedrine 2% aqueous spray two to three puffs for regular use in chronic cases.
Avoidance of precipitating or provoking causes is curative in the case of urticaria.
Conclusion:
Out of two types of urticaria, acute can be treated permanently with medications. However, in the case of chronic urticaria, the infection will relapse once every six days. So timely transport to the emergency department is needed when the patient suffers from the symptoms of chronic urticaria.
