Hives, also known as urticaria, appear as raised, red, and swollen patches of varying sizes on the skin. These patches may resemble mosquito or ant bites or form irregular shapes like a map. Hives can occur on any part of the body, and in some cases, swelling may also develop in soft tissues (a condition known as angioedema), particularly around the eyelids and lips.
Hives: Symptoms and Reactions
Hives often appear suddenly, with intense itching as the primary symptom. The rash typically fades within 24 hours without leaving marks but may reappear in different areas of the body. If angioedema occurs, the swelling can last for more than 24 hours and may be accompanied by pain.
Types of Hives
Hives can be classified into 2 types based on the duration of symptoms:
- Acute Urticaria: Hives that persist for no longer than 6 weeks.
- Chronic Urticaria: Hives that occur at least twice a week and continue for more than 6 weeks.
Factors and Causes of Hives
- Food: Seafood, preservatives, and certain food colorings.
- Medications: Allergic reactions to certain drugs.
- Infections: Viral, bacterial, or fungal infections, as well as parasitic infestations.
- Endocrine Disorders: Conditions such as thyroid disease.
- Physical Triggers: Some individuals may develop hives due to abnormal skin reactions to heat, cold, pressure, sunlight, or exercise.
- Contact Allergies: Hives can appear where the skin comes into contact with allergens such as latex, pet dander, plants, or certain foods.
- Insect Venom Reactions: Some individuals develop hives as a reaction to bee or wasp stings.
- Cancer: Certain cancers, such as lymphoma, may be associated with chronic hives.
- Autoimmune Reactions: In some cases, the immune system mistakenly triggers the release of chemicals in the skin, leading to hives.
- Unknown Causes: The majority of chronic hives cases have no identifiable cause, even after thorough medical evaluation. This may suggest that current medical knowledge is still insufficient to explain all underlying factors.
Regardless of the cause, individuals experiencing hives should seek medical consultation to determine potential triggers. Identifying and addressing the underlying cause can help manage or even completely resolve the condition.
Approaches for Diagnosing the Causes of Hives
- Medical History Assessment: Evaluating potential triggers such as physical stimuli, medications, food, insect bites, or infections.
- Physical Examination: Assessing the severity of the condition and identifying possible underlying causes.
- Laboratory tests or Specific Examinations may include skin prick testing (SPT) for allergies or blood tests to identify specific allergy triggers (specific IgE). The doctor will decide whether to order these tests based on the indications found during the medical history and physical examination.
Treatment for Urticaria (Hives)
- Identify the cause and, if possible, avoid or treat the triggers of the condition.
- Antihistamines (antiallergic medications): The response to antihistamines may vary among patients. Some individuals may achieve good results with just one type of antihistamine, while others may require a change to a different antihistamine or the use of multiple medications to control symptoms.
- Other medications: If the patient experiences severe symptoms and the hives do not respond well to antihistamines, the doctor may consider prescribing other medications that inhibit the production and release of chemical mediators in the skin, which are responsible for causing the hives.
Prognosis of Urticaria (Hives)
- Acute Urticaria (when the cause can be identified and treated): When antihistamines are taken, the hives usually resolve within 1-2 weeks. In some cases, even if the cause is unclear, the condition may persist and require continuous use of antihistamines, which can eventually lead to chronic urticaria.
- Chronic Urticaria: For patients whose causes have been identified and treated, the hives typically resolve with antihistamines, similar to cases of acute urticaria. However, if the cause cannot be identified or is difficult to treat, the condition often becomes chronic. In such cases, medication adjustments are necessary to control the condition over the long term. It may take about 2-5 years before the medication can be stopped. However, most cases of chronic urticaria tend to be mild in severity.
