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Chronic Spontaneous Urticaria

Last updated Jan. 2, 2022

Reviewed by: Lester Fahrner, MD

Approved by: Krish Tangella MD, MBA, FCAP

Chronic Spontaneous Urticaria is a form of chronic urticaria in which the signs and symptoms occur in the absence of a known trigger.

What are the other Names for this Condition? (Also known as/Synonyms)

  • Urticaria, Chronic Spontaneous type

What is Chronic Spontaneous Urticaria? (Definition/Background Information)

  • Urticaria is a common inflammatory condition of skin that results in weals (red skin  papules or plaques with itching) and/or angioedema (swelling due to fluid accumulation). It is seen in individuals of a wide age group and may be described as acute or chronic, based on the duration of the signs and symptoms
  • Chronic urticaria, by definition, is a skin condition that lasts over 6 weeks. The signs and symptoms are observed for a long-term; daily, or periodic occurrence of weals, may be noted. It can be localized or widespread
  • Chronic Spontaneous Urticaria is a form of chronic urticaria in which the signs and symptoms  occur in the absence of a known trigger. Thus, in many cases, no cause is established for Chronic Spontaneous Urticaria
  • However, it is believed that the condition may be triggered by factors that include bacterial infections, internal  infestations caused by parasites, and autoimmune disorders including lupus,  rheumatoid arthritis, and Graves’ disease
  • Any region of body skin may be affected, but usually the head and neck, chest and back, arms and legs are involved. Intense itching may lead to skin ulceration and scarring, which can cause emotional stress from cosmetic concerns
  • Chronic Spontaneous Urticaria is treated symptomatically and by treating the underlying condition, if any. The treatment may involve the use of topical ointments and creams, antihistamines, and immunosuppressive medication, in case of severe signs and symptoms. The prognosis with adequate treatment is usually good, although the condition may recur

Who gets Chronic Spontaneous Urticaria? (Age and Sex Distribution)

  • Chronic Spontaneous Urticaria can affect both children and adults, though it is more often seen in adults
  • Both males and females are affected
  • There is no race or ethnic preference observed

What are the Risk Factors for Chronic Spontaneous Urticaria? (Predisposing Factors)

The risk factors for Chronic Spontaneous Urticaria include:

  • Infections caused by bacteria including Helicobacter pylori infection
  • Roundworm infection

The following autoimmune disorders may be associated with Chronic Spontaneous Urticaria:

  • Systemic lupus erythematosus (SLE)
  • Rheumatoid arthritis (RA)
  • Graves’ disease
  • Hashimoto’s thyroiditis
  • Celiac disease
  • Type 1 diabetes
  • B12 vitamin deficiency anemia (or pernicious anemia)

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Chronic Spontaneous Urticaria? (Etiology)

Urticaria can be caused by a variety of factors. The condition develops due to the release of chemical substances, such as histamines, platelet activating factor, and cytokines (example bradykinin), from inflammatory cells called mast cells and basophils.

  • Chronic urticaria may be caused by an underlying infection, through hypersensitivity on exposure to certain substances causing an allergic reaction, or due to body’s immune system attacking one’s own body
  • It is believed that in nearly 40-50% of chronic urticaria cases, it may be an autoimmune reaction, when the body’s own defense mechanism is triggered following exposure to a stimulus, resulting in skin symptoms
  • In Chronic Spontaneous Urticaria, the underlying cause is not well-established. It occurs without a known trigger (idiopathic), but the potential causes may include parasitic gastrointestinal  (roundworm) infections and autoimmune conditions including celiac disease, RA, SLE, pernicious anemia, insulin-dependent diabetes mellitus, among others

What are the Signs and Symptoms of Chronic Spontaneous Urticaria?

The signs and symptoms of Chronic Spontaneous Urticaria may be mild or severe, localized or diffused (and sometimes, extensive), and can vary from one individual to another. The signs and symptoms of Chronic Spontaneous Urticaria include the following:

  • Initially, localized itching of skin may be observed; the skin may appear swollen
  • Formation of skin rashes or weals (wheals) that are associated with redness (or pinkish discoloration) and intense itching
  • The skin surrounding the affected area (weal) may be normal skin color or appear red (erythema)
  • The weals may change in shape and size; weals may be spherical, arranged in a random form, or ring-like pattern
  • In some individuals, there may be a burning sensation accompanying itching
  • Vigorous scratching may cause excoriations or bruising
  • Individual weals may vary in size from a few mm to few cm; but numerous weals covering a large area of the body skin are usually observed
  • The weals may last for several minutes to up to a day; few cases are non-itchy
  • Urticaria can occur in any part of the body; it can be localized or widespread or extensive
  • In some cases, it can lead to hyperpigmentation (increased skin pigmentation) or hypopigmentation (decreased skin pigmentation)
  • When pressure is applied on the hives, it blanches (becomes pale or white in color)
  • Scratching can result in worsening of the symptoms and lead to further skin complications such as ulceration and secondary infections
  • Angioedema: It may or may not occur with chronic urticaria
    • Angioedema is swelling due to fluid accumulation in the mucus membranes or deep within the skin. This lasts for up to 3 days, it can be also itchy
    • Angioedema usually occurs focally; most common sites are the head and neck region, hands, feet, and genitalia. In the head and neck region, it can involve the eyelids, lips, oral cavity, or larynx
  • Pain, pain on touch

The itching and symptoms may be worsened by substance or factors such as viral infections, tight clothing, food and drug allergies, and heat.

How is Chronic Spontaneous Urticaria Diagnosed?

A diagnosis of Chronic Spontaneous Urticaria may involve the following tests and examinations:

  • Physical examination of the skin and medical history evaluation
  • Skin allergy testing, or RAST of ImmunoCap blood testing for allergies
  • Blood test to detect various antibodies against allergens including:
    • Complete blood count (CBC) test
    • Antinuclear antibody (ANA) test
    • Erythrocyte sedimentation rate (ESR) test
    • Serum level of complement
    • Serum C-reactive protein blood test
  • Tests to rule-out other underlying autoimmune conditions and infections
  • Physical hot and/or cold provocation test
  • Skin biopsy: A skin biopsy is performed and sent to a laboratory for a pathological examination. The pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis

In Chronic Spontaneous Urticaria, the symptoms are assessed using a tool called the Urticaria Activity Scoring (UAS) System.

A differential diagnosis may be considered to eliminate certain skin conditions, prior to arriving at a definitive diagnosis. The following conditions may be considered:

  • Urticaria caused by a detectable and definable allergen trigger
  • Physical urticaria triggered by cold, exercise, vibration, or water
  • Polymorphous light eruption
  • Chronic itching due to a variety of other causes
  • Contact urticaria
  • Dermatitis herpetiformis
  • Drug eruptions of skin
  • Eczema
  • Erythema multiforme
  • Insect bites
  • Pemphigoid - urticarial phase
  • Pityriasis rosea
  • Polymorphous eruption of pregnancy
  • Urticarial vasculitis
  • Autoinflammatory disorders such as familial cold autoinflammatory syndrome (FCAS) and others

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Chronic Spontaneous Urticaria?

The following complications of Chronic Spontaneous Urticaria may be noted:

  • Intense scratching may result in skin scarring
  • Itching can lead to ulceration of skin causing superimposed bacterial and fungal skin infections
  • Severe cases can cause disruption in sleep 
  • Cosmetic concerns leading to stress
  • Frequent episodes of urticaria can affect the quality of life resulting in severe stress. This severe stress can in-turn be a trigger for further worsening of the condition
  • Involvement of the larynx due to angioedema, may be life-threatening and a medical emergency. If the larynx is involved, it can result in sudden breathing difficulties due to laryngeal edema
  • Severe chronic urticaria can result in anaphylactic shock, which is a potentially life-threatening medical condition

How is Chronic Spontaneous Urticaria Treated?

The treatment depends upon the severity of the signs and symptoms. In severe cases, an allergy specialist may be consulted. The treatment measures for Chronic Spontaneous Urticaria may include:

  • Cooling the skin using moist towels
  • Topical steroid treatment that may include moisturizing creams to soothe the skin condition
  • Systemic steroids given as a short course
  • Antihistamine therapy
  • Monthly injections of omalizumab
  • Immunosuppression therapy for severe symptoms: Use of immune modulators or medications that modulate immunity
  • Undertaking treatment of any underlying infections or autoimmune disorders accordingly (if necessary)
  • Patient education in understanding the condition is beneficial
  • Stress management for severe and chronic conditions

In some cases of idiopathic chronic urticaria, there is no cure and only management of the symptoms, as they occur, are undertaken.

How can Chronic Spontaneous Urticaria be Prevented?

Chronic Spontaneous Urticaria may not be prevented, since no causative factors are identified. However, the following factors may be considered:

  • Appropriately treat acute urticaria with a mixture of non-sedating and sedating antihistamines
  • Treating bacterial and parasitic infections early and appropriately
  • Treating autoimmune disorders adequately
  • Avoiding exposure to factors that can aggravate the condition

What is the Prognosis of Chronic Spontaneous Urticaria? (Outcomes/Resolutions)

  • The prognosis of Chronic Spontaneous Urticaria is generally good with suitable treatment, although the condition is known to recur
  • Anaphylactic reaction/shock can be fatal without treatment

Additional and Relevant Useful Information for Chronic Spontaneous Urticaria:

Please visit our Skin Care Health Center for more physician-approved health information:


What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

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Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: Sept. 27, 2017
Last updated: Jan. 2, 2022