Ebastine for Sun Allergy (Polymorphic Light Eruption)
Ebastine can be used as a treatment option for sun allergy (photodermatoses), though it is not considered first-line therapy and evidence is limited to small studies showing benefit primarily in solar urticaria rather than polymorphic light eruption specifically. 1
Evidence for Antihistamines in Photodermatoses
The British Association of Dermatologists guidelines establish that antihistamines are regarded as standard therapy for solar urticaria (a type of sun allergy), though they note that a substantial proportion of patients receive only modest benefit. 2 High-dose H1 antihistamines are frequently prescribed, following recommendations made for chronic urticarias in general. 2
Specific Evidence for Ebastine
A clinical study of 50 patients with photo-allergic dermatoses (including 15 with solar urticaria, 20 with solar erythema, and 15 with solar eczema) demonstrated that ebastine 10 mg daily for 10 days resulted in complete itch disappearance in 87% of patients, reduction in 10%, with only 3% experiencing persistent itch. 1
Ebastine is a well-established second-generation H1-antihistamine with proven efficacy in allergic rhinitis and chronic urticaria, administered once daily at 10-20 mg. 3, 4, 5
Practical Treatment Approach
When to Consider Ebastine
Use ebastine 10 mg once daily as an adjunctive treatment for symptomatic relief of pruritus and urticarial reactions in photodermatoses, particularly solar urticaria. 1
For moderate to severe symptoms, ebastine 20 mg daily may be more effective than standard 10 mg dosing. 3, 4
Combine with broad-spectrum sunscreen (SPF ≥30) and photoprotection measures, as antihistamines alone provide incomplete disease control. 6
Advantages of Ebastine
Once-daily dosing with rapid onset of action and 24-hour efficacy. 3, 5
Minimal sedation risk—ebastine has one of the lowest risks for adverse cognitive/psychomotor effects among antihistamines. 3, 4, 5
No dose adjustment needed in elderly patients or those with renal or mild-to-moderate hepatic impairment. 3
Important Limitations and Caveats
The evidence for ebastine specifically in photodermatoses is limited to one small study of 50 patients, and no randomized controlled trials exist comparing it to other antihistamines for this indication. 1 The British guidelines note that RCTs are not available for antihistamines in solar urticaria itself. 2
For polymorphic light eruption specifically, phototherapy (PUVA or NB-UVB) administered in early spring is the more established treatment approach when photoprotection alone is insufficient. 2
Drug Interactions to Avoid
Do not co-administer ebastine with ketoconazole or macrolide antibiotics due to pharmacokinetic interactions, though no cardiovascular effects have been described at therapeutic doses. 4
Alternative Considerations
If ebastine provides inadequate symptom control, consider other second-generation antihistamines such as cetirizine, which may have superior efficacy for some allergic conditions, though it carries slightly higher sedation risk (13.7% vs 6.3% placebo). 7
For refractory cases of photodermatoses not responding to antihistamines and photoprotection, referral to dermatology for specialized phototherapy or other interventions is warranted. 2, 6