Urticaria Causes

What expert says | Triggers | Types | Prognosis

Urticaria is the most common skin condition that has needed emergent medical care most often. Almost 20% of the world population has had an attack of urticaria at one time or another. Acute urticaria is more due to the hypersensitivity of our skin to certain foods, physical factors like heat, sunlight, or to some chemicals, pollen and nettles, medications, diseases and infections etc and chronic urticaria is due to autoimmune disorder and other conditions.

What experts say

When histamine and other chemicals from under the skin surface are released because of degranulation of mast cells, these cause small blood vessels to leak plasma. Inflammation and fluid accumulation under the skin are the results of this leakage and show up as the rash called urticaria. What can cause this histamine release is exactly not known though. But there are a lot of triggers that cause this reaction to happen and urticaria can be diagnosed easily.

Triggers

• Medicines NSAIDs like aspirin, some antibiotics, ACE inhibitors.
• Infections like cold, liver infections, flu, mononucleosis and intestinal infections.
• Medical conditions like thyroid disease, other autoimmune diseases, lupus.
• Foods and food additives – nuts, fruits like berries, tomatoes, chocolate, shellfish, eggs and fish.
• Extreme climate/temperature – extreme hot and cold weather and excess sunlight.
• Excessive sweating – perspiration from vigorous exercise, physically stressful activities and emotional stress.
• Animal dander, dust motes, pollen, some plants.
• Insect bites.
• Pets.
• Latex, nickel and industrial chemicals.
• Use of tight clothing, synthetics, wool next to skin.

Types

• Acute urticaria – when the rash or hives last for about six weeks or even less. Maybe due to infections, medications, allergic reaction to some food items, chemicals, heat, cold, pressure, pollens, nettles, latex, food additives.
• Chronic urticaria – when the rash lasts for a longer period, more than six weeks; and with difficult-to-identify causes; can be from chronic infection, hormonal disorder, autoimmune response etc.
• Physical urticaria – when physical stimulus/contact of the skin happens from a cause like heat or cold, sun exposure, exercise and sweating, and vibration, pressure and sweating etc.
• Dermatographism – happens when skin is scratched, stroked etc
• Urticaria due to underlying medical diseases – like urticaria pigmentosa, cutaneous vascultis, serum sickness etc.
• Urticaria due to hereditary causes – like angioneurotic edema, vibratory angioedema, familial cold urticaria .
• Contact urticaria – induced by biologic or chemical skin contact.
• Autoimmune urticaria – its of autoimmune eitolgy.
• Idiopathic urticaria – unknown cause

Angioedema is similar to acute urticaria except massive edma involves the subcuatenous tissue and is clinically characterized by asymmetric swelling of tissues with overlying skin being normal and patient complains of burning more than itching. It can affect internal organs and is treated as a medical emergency.

Prognosis

Acute urticaria patients may also develop acute angioedema. There are lot of effective treatment plans for urticaria. With identifying the triggers, and avoiding them, acute urticaria is managed more easily than chronic urticaria. Though chronic urticaria’s symptoms recur, with correct medical treatment and life style changes to manage the triggers, patients can avoid frustration or depression and enjoy an active and normal life.

• References

• • Indian Journal of Dermatology, Venereology & Leprology – Evaluation of the Causes of Physical Urticarias (Mohan Singh, Surrinder Kaur, AJ Kanwar) view
  • American Association of Dermatology – Hives: Who gets and Causes view
  • Emedicine Health – Hives and Angioedeme Causes view
  • NHS UK view
  • University of Maryland Medical Center – Urticaria view
  • John Hopkins Medicine – Urticaria and Hives view