What is the recommended treatment for urticaria in pregnancy?

Treatment of Urticaria in Pregnancy

When urticaria treatment is necessary during pregnancy, use second-generation antihistamines—specifically cetirizine or loratadine—as they are FDA Pregnancy Category B drugs with the best safety profile, though chlorphenamine remains an acceptable alternative based on its long safety record. 1, 2, 3

General Approach to Antihistamines in Pregnancy

• Ideally avoid all antihistamines during pregnancy, especially in the first trimester, though none has been proven teratogenic in humans 1, 2, 3
• When treatment is medically necessary, the risk-benefit analysis favors treatment over uncontrolled urticaria that may compromise maternal comfort and safety 4
• Hydroxyzine is specifically contraindicated during early pregnancy and should never be used 1, 2, 3

First-Line Treatment Algorithm

Preferred Agents

• Cetirizine and loratadine are the antihistamines of choice as FDA Pregnancy Category B drugs, meaning no evidence of fetal harm exists though controlled human studies are lacking 1, 2, 3, 5
• Chlorphenamine (chlorpheniramine) is often selected by UK clinicians when antihistamine therapy is necessary due to its long safety record, despite being a first-generation antihistamine 1, 2, 3
• Real-world data from the PREG-CU study showed that 35.1% of pregnant CU patients used standard-dose second-generation antihistamines during pregnancy with no increased risk of medical problems at birth 6

Dosing Strategy

• Start with standard doses of the chosen antihistamine 2, 3, 7
• If symptom control is inadequate after 2-4 weeks, consider increasing the dose up to 4 times the standard dose, weighing potential benefits against risks 2, 3, 7
• The PREG-CU study found 5.6% of patients used high-dose second-generation antihistamines during pregnancy without adverse outcomes 6

Second-Line Treatment: Omalizumab

• Omalizumab may be used during pregnancy for antihistamine-resistant urticaria, particularly when urticaria is severe and uncontrolled 5
• The PREG-CU study documented 5.6% of pregnant patients using omalizumab with no link between treatment and medical problems at birth 6
• Standard dosing is 300 mg every 4 weeks 2, 3, 7
• Allow up to 6 months to evaluate response before considering alternatives 2, 3, 7

Corticosteroids: Use Sparingly

• Limit oral corticosteroids to short courses (3 days) only for severe acute exacerbations (e.g., prednisolone 50 mg daily for 3 days, adjusted for pregnancy) 1, 2
• Short tapering courses over 3-4 weeks may be necessary for severe cases, but long-term use should be avoided 1
• Use lower doses than standard adult dosing when possible 2

Medications to Avoid During Pregnancy

• Hydroxyzine is contraindicated in early pregnancy 1, 2, 3
• First-generation antihistamines other than chlorphenamine should generally be avoided due to sedating effects, though chlorphenamine itself is acceptable 1, 5
• Cyclosporine, methotrexate, mycophenolate mofetil, and azathioprine should be avoided 5
• Intranasal antihistamines should be avoided 5

Critical Safety Considerations

Emergency Management

• Intramuscular epinephrine remains life-saving for anaphylaxis or severe laryngeal angioedema even during pregnancy 1, 2
• Dosing: 0.5 mL of 1:1000 (500 µg) for adults and adolescents over 12 years 1, 2
• Fixed-dose epinephrine auto-injectors (300 µg) should be prescribed for patients at risk of life-threatening attacks 2, 7

Pregnancy Outcomes Data

• The PREG-CU study showed preterm birth rate of 10.2% in CU patients, similar to population norms 6
• Emergency referrals for CU increased the risk of preterm birth, emphasizing the importance of maintaining disease control during pregnancy 6
• Over 90% of newborns were healthy at birth regardless of treatment used 6
• Caesarean delivery rate was 51.3%, though not specifically linked to urticaria treatments 6

Practical Management Pitfalls

• Do not withhold necessary treatment out of excessive caution—uncontrolled urticaria requiring emergency care poses greater risks than appropriate antihistamine use 6
• Avoid switching from an effective pre-pregnancy regimen to a less effective one solely due to pregnancy, as this may lead to disease flares and emergency presentations 4, 6
• Pregnancy-appropriate regimens should ideally be discussed with all women of childbearing age before conception, as most pregnancies are unplanned and peak fetal vulnerability begins when a period is due 4

Adjunctive Measures

• Identify and minimize aggravating factors including overheating, stress, alcohol, and certain medications (aspirin, NSAIDs, codeine) 2, 3, 7
• Cooling antipruritic lotions (calamine or 1% menthol in aqueous cream) provide symptomatic relief without systemic absorption 2, 3
• Patient education about disease course during pregnancy: urticaria improves in 50% of pregnant patients but worsens in one-third 8