Urticaria in children (Paediatric guideline)

Acute urticaria

• is defined as the occurrence of wheals, angioedema, or both for 6 weeks or less.

Chronic urticaria 

• is defined as the occurrence of wheals, angioedema, or both for MORE THAN 6 weeks (daily or almost daily or an intermittent / recurrent course).

• Pruritus is widely considered the most distressing aspect, often compelling patients to seek urgent relief.

• Flares can occur without warning.

• Individual wheals rarely persist longer than 12 to 24 hours.

• Parents can mark around a wheal with pen to help track the pattern and support the diagnosis.

Urticaria may be spontaneous or inducible (eg, through direct contact with a trigger, cold or pressure urticaria, heat, UV sunlight, water, exercise, dermographism / rubbing and vibrations). Psychological stress may exacerbate (but does not cause) urticaria.

• Symptomatic dermographism occurs in 5% of the background population.

• Symptoms occurring overnight would NOT be typical of allergy driven urticaria.

Most common identifiable triggers in children are:

• Infection: mainly viral (the most common cause in children). Most often acute / resolves quickly

• Drugs: particularly penicillins, the second most common cause in children

• ACE inhibitors: usually cause pure angioedema

• A food history is helpful but usually a minor cause for chronic urticaria

History should include:

• Duration

• Frequency

• Distribution of rash

• Triggering factors

• Association with angioedema

• Relationship to travel

• Menstrual cycle

• Foods

• Medication

• Infections

• Stress

Acute urticaria: 

Often is self-limiting, usually does not require a diagnostic workup, apart from history taking for possible trigger factors.

Tests: We recommend against any routine diagnostic measures in acute spontaneous urticaria.

Management: 

Treat underlying cause.

FIRST LINE treatment in children is symptomatic relief with an antihistamine. 

• Children 1 month to 1 year: Chlorphenamine (not licensed under 1 year of age, but BNFC dosing from 1 month)

The following second generation / newer, "non-sedating" antihistamines do not cross the blood brain barrier as easily as first generation and cause fewer side effects.

• Children 1 year and over: Cetirizine (not licensed under 2 years, but BNFC dosing for 1 year of age)

• If cetirizine NOT tolerated or NOT effective:

  • Children 2 years and over: Loratadine

  • Children 12 years and over: Loratadine or fexofenadine 

• A further breakthrough dose could be offered, once in the day, as required.

See BNFC or manufacturer's information for full prescribing details. 

Chronic Urticaria

Identify triggers: Ensure no aggravating factors (eg, NSAID)

Management: The primary goal in treating is to achieve complete symptom control, defined as the resolution of hives, itch, and angioedema.

• For children under 1 year: discuss with Paediatrics or refer. 

• For children 1 year and over: NHS Highland Paediatric and Dermatology departments recommend titrating non–sedating, second generation antihistamine (updosing).

  • Dose escalation of antihistamines may be required up to two-fold the standard BNFC dosage. If further updosing is required (up to four-fold), refer to Paediatrics.

  • Antihistamine choices are as per acute urticaria:

    • Children 1 year and over: Cetirizine (not licensed under 2 years, but BNFC dosing for 1 year of age)

    • If cetirizine not tolerated or not effective:

      • Children 2 years and over: Loratadine

      • Children 12 years and over: Loratadine or fexofenadine 

  • Although 'updosing' is off-label, 'updosing' has been suggested in the national and international guidelines for urticaria since the year 2000 and, to date, no serious adverse events have yet been reported, nor has a side effect attributed to long-term intake and potential accumulation been reported in the literature. Scenario: Managing urticaria | Management | Urticaria | CKS | NICE

  • A single antihistamine only is preferred and it should then be slowly titrated to maximum dose.

  • Titration of antihistamines should be undertaken slowly by one increased dose every 2 weeks.

  • An alternative single antihistamine can be considered within 6 weeks, if there has been no improvement with a titrated dose.

Refer to Paediatrics

• Children under 1 year of age with chronic urticaria (or discuss via Clinical Dialogue)

• Type 1 (IgE mediated) allergy

  • Note: Urticaria due to IgE mediated allergy typically occurs within minutes of exposure to the allergen (maximum 1 to 2 hours) and lasts for a short period (minutes to a few hours).

• Anaphylaxis (a medical emergency and requires immediate treatment, expectant management) See Anaphylaxis (Guidelines)

• Long-standing and/or uncontrolled disease despite 'updosing' to double dose of non-sedating antihistamine every 2 to 4 weeks (up to 2 months of treatment)

• Recurrent unexplained fevers

• Joint / bone pain

• Significant fatigue

• Recurrent angioedema without urticaria. ? HAE / AAE

Refer to Dermatology

• Refer if any diagnostic uncertainty

• Refer urgently if any features of urticarial vasculitis (painful urticarial, resolution with bruising)

Paediatrics

• Titrate dose of non-sedating antihistamine to fourfold (4x) every 2 to 4 weeks (up to 2 months of treatment)

If no response/suboptimal control

• Request tests: Basic tests include FBC, U&E, LFT, CRP, Thyroid function, serum glucose, coeliac screen, total IgE and thyroid antibodies, and ANA.

• Send complement screen (C3 C4) if recurrent angioedema without urticaria

• Where formulary choices have been not tolerated or are ineffective, to consider non-formulary alternatives (eg, desloratidine and levocetirizine). 

• AND: Refer to Dermatology

• AAE: acquired angioedema
• ANA: antinuclear antibody
• CRP: C-reactive protein
• CSU: chronic urticaria
• FBC: full blood count
• HAE: hereditary angioedema
• LFT: liver function test
• NSAID: non-steroidal anti-inflammatory drug
• UE: urea and electrolytes