Long-term treatment with bilastine has also been investigated in an open-label, single-arm, one-year safety study.34 This study demonstrated that bilastine significantly reduced all rash and itch symptoms at the first time point (2 weeks), and this response was maintained throughout the 52 weeks showing that bilastine does not cause tachyphylaxis. Throughout the treatment period bilastine was well tolerated with only 2.5% of patients reporting mild or moderate bilastine-related adverse events and only two reports of somnolence similar to placebo-treated patients.34
Bilastine was also investigated in three up-dosing studies in patients with CSU and cold contact urticaria.31-33 At doses of 40 and 80 mg, bilastine further improved upon the symptom score outcomes for urticaria patients. Since bilastine is a non-brain penetrating antihistamine it is an ideal AH for up dosing the daily dose four-fold in difficult-to-treat urticaria.8
Pruritus associated with dermatological conditions
The involvement of histamine in pruritus associated with various skin conditions varies. For example, histamine H1‐receptor- induced pruritus in AD is lower than that in patients with CSU.34,36 Two studies that included patients with CSU or pruritus associated with skin diseases showed that bilastine is effective in reducing itch scores for skin conditions such as AD, prurigo and cutaneous pruritus (Table 2).34,32 One of these studies allowed for 52 weeks of treatment, and no loss of drug sensitivity at 20 mg once daily was seen.34
This second-generation AH is effective for chronic pruritus related to skin diseases such as AD and demonstrates that second-generation AHs may be an effective adjunct to AD treatment, in addition to patient education, a primary skincare plan, the use of moisturizers, and topical anti-inflammatory therapy.
The cases presented here by the authors focused on the use of bilastine in conditions such as SAR, PAR, and chronic urticaria, as well as less common but challenging conditions such as urticarial vasculitis and pruritus in skin conditions.
Advisors discussed the use of AHs, then presented, reviewed, and critiqued the various cases. A final consensus vote (75% consensus needed) on the cases revealed a unanimous consensus on ten different cases for inclusion in the publication.
SAR and PAR
Table 3 discusses a 21-year-old female with PAR (Case 1) and a 9-year-old boy with a pet allergy and a history of seasonal allergies (Case 2). Both patients tolerated bilastine very well and had a rapid response to treatment with no adverse events reported. The panel members noted that in cases 2 and 5 bilastine is presently off-label in the pediatric population; however, phase 3 clinical data demonstrates that bilastine is safe for use in children as young as 2 years of age.37 As well, bilastine was recently approved in Europe for children age 6 – <12 years of age and in Mexico for children 2 – <12 years of age. The panel members proposed a liquid pediatric formulation of the AH is needed, especially for use in children down to 2 years of age.
CSU and dermatographism or angioedema
Table 4 shows three cases: A 19-year-old female with CSU and dermatographism (Case 3), a 24-year-old female with CSU and angioedema (Case 4), and a 12-year-old male with an 8-month history of daily urticaria and intermittent angioedema (Case 5).
The patient described in case 4 had previously used oral diphenhydramine 25 mg, sometimes up to 3 times/day (TID), which only controlled pruritus and swelling for a few hours. After one month of bilastine use, her condition had cleared after which the AH was used PRN. Her quality of life dramatically improved, positively impacting her study, quality of sleep, social life, and self-image. According to the panel members, the sedation caused by using first-generation AHs is not helpful in treating pruritus and should be discouraged because of potentially serious side effects.1-6,12
Inducible urticaria: cold urticaria and cholinergic urticaria
Table 5 presents two cases with inducible urticaria: A 29-yearold female with cold contact urticaria (Case 6) and a 22-year-old male with cholinergic urticaria (Case 7). The patient in Case 6 received previous treatment with cyproheptadine 16 mg, cetirizine 40 mg, and at bedtime doxepin 75 mg, which caused sedation and systemic side effects. After changing her medication to bilastine 40 mg twice daily, the patient had fewer and less severe outbreaks and no systemic symptoms.
The correct diagnosis for the 22-year-old male with cholinergic urticaria took a long time; in fact, before proper diagnosis, the patient was even treated (unsuccessfully) for conditions such as scabies and AD. However, with the combination of proper education on his condition, and bilastine 20 mg daily used as needed, this patient has recovered the confidence to exercise again, thereby improving his QoL significantly. The panel agreed that education on cholinergic urticaria and its differential diagnoses is crucial for successful treatment.
Table 6 presents case 8 about a 43-year-old female with urticarial vasculitis, which is difficult to diagnose from a biopsy. Consequently, for over 8 years after the first symptoms occurred, numerous biopsies showed negative results. Eventually, however, confirmation of the condition from a biopsy was obtained; the patient’s condition improved significantly after she was prescribed bilastine.