From the Guidelines
Papular urticaria treatment should focus on relieving symptoms and preventing further insect bites, with antihistamines being the mainstay of therapy, as they show a good response in over 40% of patients 1. When managing papular urticaria, it is essential to consider the following key points:
- Advice on general measures and information can be helpful for most patients, especially if an avoidable physical or dietary trigger can be identified 1.
- Topical corticosteroids, such as hydrocortisone 1% cream, can be applied twice daily for 7-10 days to reduce inflammation and itching.
- Oral antihistamines, like cetirizine (5-10mg daily) or diphenhydramine (25-50mg every 6 hours), help control itching, with diphenhydramine being particularly useful at night due to its sedating effects.
- Prevention is crucial and involves identifying and eliminating the source of bites, using insect repellents containing DEET (10-30%), wearing protective clothing, and washing bedding in hot water.
- Cool compresses and calamine lotion can provide additional symptomatic relief.
- Antibiotics, such as cephalexin (500mg four times daily for adults), are only needed if secondary bacterial infection occurs, indicated by increased redness, warmth, pain, or purulent discharge. It is crucial to note that the treatment approach should prioritize relieving symptoms and preventing further insect bites, with a focus on antihistamines as the primary treatment option, as supported by the guidelines for evaluation and management of urticaria in adults and children 1.
From the Research
Treatment Options for Papular Urticaria
Papular urticaria is a common childhood disorder characterized by chronic or recurrent papules caused by a hypersensitivity reaction to insect bites 2. The treatment for papular urticaria is similar to that of chronic urticaria.
- Second-generation antihistamines are considered first-line agents in the treatment of chronic urticaria due to their safety and efficacy profile 3.
- Some patients may require higher doses of H1 antihistamines alone or in combination with other classes of medications, including H2 antihistamines, leukotriene receptor antagonists, or first-generation H1 antihistamines 3.
- Omalizumab, a humanized monoclonal anti-immunoglobulin E, has been approved for the treatment of chronic urticaria that is unresponsive to H1 antagonists 3.
- H1 antihistamines and short-term systemic corticosteroids are preferred for the treatment of urticaria, with H2 antagonists added in resistant cases 4.
- Other treatment options, such as cyclosporine and leukotriene receptor antagonists, may be considered in missed events 4.
Comparison of Antihistamines
A study comparing the effects of loratadine and cetirizine on serum levels of neuropeptides in patients with chronic urticaria found that:
- Both loratadine and cetirizine decreased serum levels of neuropeptide Y and vasoactive intestinal peptide 5.
- Cetirizine was significantly more effective than loratadine in lowering serum levels of stem cell factor 5.
- The predominant effect of cetirizine compared to loratadine on reducing serum stem cell factor levels may be explained by the anti-inflammatory properties of cetirizine 5.