What Is Urticaria?
Urticaria is mostly a harmless and self-limiting skin condition that appears as patches of raised, red, and severely itchy bumps and swellings, that keep appearing and disappearing, and is usually triggered by an allergic response, and sometimes by autoimmune conditions. The urticarial bumps or weals vary in size and shape, and may last from a few minutes to a few hours, and usually resolve without leaving any scars or damage to the skin.
Is this condition a medical emergency?
Hives are not a medical emergency, but it may lead to serious complications such as anaphylaxis which may require immediate medical attention.
Types of this condition
Hives can be of the following types:
- Acute Urticaria: Lasts for less than 6 weeks.
- Chronic Urticaria: Lasts for more than 6 weeks.
- Spontaneous Chronic Urticaria: It does not have a specific cause or trigger, or it may be due to autoimmune causes.
- Inducible Chronic Urticaria: It is triggered by a cause.
- Symptomatic Dermographism: An exaggerated form of the redness and swelling on the skin when firmly stroked.
- Cold Urticaria: The redness and swellings develop after being exposed to cold objects, and cold weather.
- Cholinergic Urticaria / Heat Bumps: Caused by a rise in core body temperature with sweating.
- Contact Urticaria: Caused immediately on contact with a triggering substance or factor.
- Delayed Pressure Urticaria: Urticaria develops after pressure is applied to the skin.
- Solar Urticaria: Urticaria develops shortly after exposure to natural sunlight or artificial light emitting ultra-violet rays.
- Heat Urticaria: Urticaria develops rapidly upon contact with a hot object or a heat stimulus to the skin.
- Vibratory Urticaria: Caused when the skin is exposed to vibrations, repetitive stretching, or friction.
- Aquagenic Urticaria: Urticaria occurs as a result of exposure to water.
Causes of urticaria
The weals or welts of hives are caused when the immune system releases substances such as histamine, bradykinin, etc, resulting in the leakage of fluid into the skin, and the subsequent swelling. The severe itching is also as a result of the presence of histamine in the layers of the skin. There may be several causes of hives and they include:
- Infections: Bacterial, viral, and parasitic
- Insects: Caterpillars and moths
- Foods: Eggs, fish, shellfish, cheese, chocolates, nuts, berries, etc
- Environmental factors: Pollen, plants, animal dander, dust, mold
- Drugs: Penicillin, NSAIDs, antihistamines
- Emotional stress
- Sunlight or UV light
- Scratching, pressure on the skin
Chronic Urticaria can be caused by all of the above and in addition to the following:
- Autoimmune diseases: Systemic Lupus Erythematosus, rheumatoid arthritis, connective tissue disorders
- Chronic diseases: Hypothyroidism, hyperthyroidism, amyloidosis, cancers, lymphoma
- Inherited autoinflammatory syndromes
Inducible Urticaria can be triggered by any of the specific causes depending on the type of Hives that is present. However, there is no trigger for a Spontaneous Urticaria.
Symptoms & signs of urticaria
The following may be seen in hives:
- Patches of red, or skin-colored and raised weals, or hives
- The weals vary in shape ranging from a few millimeters to a few centimeters.
- The weals may be round, or straight lines or curved lines.
- The weals have a central pale region with a red base and flare.
- The welts appear and fade lasting between a few minutes to a few hours.
- Severe itching
- Painful swelling of the lips, eyes, or inside the throat
- The symptoms increase in intensity when exposed to the causative factor.
Investigations are usually not required for establishing a diagnosis of Hives. In some cases of hives, the following may be needed:
- Laboratory tests: Usually indicated for chronic hives and/or recurrent urticaria.
- CBP, ESR
- Thyroid profile
- Anti-Nuclear Antibody testing
- Punch Biopsy: This is done only if Urticarial Vasculitis is suspected.
Diagnosis of urticaria
Diagnosis of hives is established based on medical history, clinical evaluation, and results of the investigations if any.
Urticaria treatment options
Acute urticaria usually does not require any treatment, as it is mostly self-limiting and resolves in a short period. Some of the symptoms however may be treated with medical management.
A. Medical management
The medical management of symptoms in acute and chronic urticaria may include:
- Anti-histamines: Such as Loratidine, Fexofenadine, Cetrizine, Levocetirizine, and act by blocking the Histamine receptors; they cause minimal drowsiness.
- H2-Blockers: Such as Cimetidine, ranitidine is used in combination with other antihistamines.
- Anti-inflammatory agents: Such as corticosteroids are used to reduce the inflammatory response, redness, and swelling.
- Leukotriene Receptor Antagonists: Such as some asthma medications like Montelukast, Zafirlukast in combination with antihistamines, can help to reduce the intensity of the immune response.
- Antidepressants: Such as Doxepin may be used in conditions that are not responding to other medications.
- Monoclonal Antibodies: Such as Omalizumab may be used in conditions that are not responding to other medications.
- Immune suppressants: Such as Tacrolimus may be used in conditions that may be due to autoimmune causes.
B. Role of diet/exercise/lifestyle changes/preventive measures
Some self-care measures that can be taken to avoid hives may include:
- Avoiding known triggers
- Avoiding scratching
- Avoiding harsh soaps and harsh cosmetics
- Using protection such as sunscreens, etc.
- Keeping a watch and making notes of possible triggers, times, etc.
The complications of hives may include:
- Severe anaphylactic reactions.
- Chronic hives can cause psychological stress such as anxiety and depression, loss of sleep, and reduced quality of life.
The prognosis for acute urticaria is excellent, as it is usually a self-limiting condition. The prognosis for chronic hives depends on the underlying cause and is usually associated with a reduced quality of life.
When to contact the doctor or hospital/How to identify the emergency or complications?
It is important to seek medical advice if the hives continue to appear over several days. It is also important to seek immediate medical attention if the following are present.
- Breathing and swallowing difficulties
- Swelling of the eyes, lips, or the tongue
Indications for hospitalization if required
Hospitalization is not required for hives, however, if complications such as anaphylaxis develop, then immediate hospitalization may be required.
Suggested clinical specialist/Departments to consult for this condition
Hives will be attended to by specialists from the departments of Allergy and Immunology, Dermatology, and/or the Emergency Department.