Evidence-based use of antihistamines for treatment of allergic conditions

Case report of an unusual allergic reaction to a routine skin prick test performed in an outpatient clinic: Diagnosis, management, and knowledge gaps

BACKGROUND

The skin prick test (SPT) is a standard procedure in allergy/immunology clinics, crucial for evaluating conditions like allergic rhinitis and food allergies. As a cornerstone in investigating immunoglobulin E-mediated allergy, it plays a vital role in diagnosing allergies, including those triggered by common dust mites like Dermatophagoides pteronyssinus, Dermatophagoides farinae, Euroglyphus maynei, and Blomia tropicalis. Despite its widespread use, adverse reactions to SPT are uncommon (15 per 100,000 patients), though the procedure is not entirely risk-free. This article presents a clinical case involving a 17-year-old female who experienced a moderately delayed allergic reaction 120 minutes post-SPT, managed effectively with subsequent symptom resolution.

METHODS

The patient, with a history of persistent rhinorrhea, itchy nose, eyes, and postnasal drip, sought consultation due to worsening symptoms. Diagnostic measures, including patient-reported outcomes and SPT with a standard aeroallergen panel, revealed sensitization to various allergens.

RESULTS

Post-test, the patient reported ocular pruritus, left eyelid swelling, and moderate rhinorrhea, persisting for about 24 hours. On the subsequent medical visit, the patient received rupatadine and deflazacort, leading to symptom resolution within 3 hours.

CONCLUSION

This article delves into a systemic allergic reaction post-SPT, emphasizing the 2 main stages of type I hypersensitivity reactions. While the acute phase involves mast cell-driven mediators within 15 minutes, the delayed phase (4-8 hours) includes de novo cytokine release. Vigilance regarding symptom onset and differentiation between mild and severe reactions is crucial. Notably, the absence of specific waiting time guidelines post-SPT underscores the need for reporting to enhance understanding and subsequent management. Performing these procedures in specialized centers with qualified professionals is essential for effectively managing potential anaphylactic reactions. Addressing these knowledge gaps will contribute to enhanced patient safety during diagnostic procedures.

Management of Allergic Rhinitis in the United Arab Emirates: Expert Consensus Recommendations on Allergen Immunotherapy

Allergic rhinitis (AR) is a chronic inflammatory condition of the upper airways caused by a type I hypersensitivity reaction triggered by environmental allergens. AR is associated with significant morbidity and affects patients' quality of life, emotional well-being, productivity, and cognitive functioning. As AR prevalence and morbidity have increased significantly worldwide, similar observations have been noted in the United Arab Emirates (UAE) with AR becoming a potential public health issue. Management of AR in the UAE is mainly provided by non-allergy specialists relying on first-line treatments such as intranasal steroids and antihistamines, with often suboptimal and short-term efficacy. Allergen Immunotherapy (AIT) is the only currently available disease-modifying treatment option in the form of either subcutaneous or sublingual allergen immunotherapy that has been proven to have long-term benefits. This article aims to provide recommendations regarding the use of AIT for managing AR in the UAE, considering both the current landscape in the Emirati healthcare system and local experience.

Drug repurposing for bacterial infections

Repurposing pharmaceuticals is a technique used to find new, alternate clinical applications for approved drug molecules. It may include altering the drug formulation, route of administration, dose or the dosage regimen. The process of repurposing medicines starts with screening libraries of previously approved drugs for the targeted disease condition. If after an the initial in silico, in vitro or in vivo experimentation, the molecule has been found to be active against a particular target, the molecule is considered as a good candidate for clinical trials. As the safety profile of such molecules is available from the previous data, significant time and resources are saved. These advantages of drug repurposing approach make it especially helpful for finding treatments for rapidly evolving conditions including bacterial infections. An ever-increasing incidence of antimicrobial resistance, owing to the mutations in bacterial genome, leads to therapeutic failure of many approved antibiotics. Repurposing the approved drug molecules for use as antibiotics can provide an effective means for the combating life-threatening bacterial diseases. A number of drugs have been considered for drug repurposing against bacterial infections. These include, but are not limited to, Auranofin, Closantel, and Toremifene that have been repurposed for various infections. In addition, the reallocation of route of administration, redefining dosage regimen and reformulation of dosage forms have also been carried out for repurposing purpose. The current chapter addresses the drug discovery and development process with relevance to repurposing against bacterial infections.

Advances in co-pathogenesis of the united airway diseases

According to the concept of "united airway diseases", the airway is a single organ in which upper and lower airway diseases are commonly comorbid. A range of inflammatory factors have been found to play an important role in the chain reaction of upper and lower airway diseases. However, the amount of research on this concept remains limited. The underlying mechanism of the relationship between typical diseases of the united airway, such as asthma, allergic rhinitis, and chronic sinusitis, also needs to be further explored. This review highlights the interaction between upper and lower respiratory diseases gathered from epidemiological, histoembryology, neural mechanistic, microbiological, and clinical studies, revealing the relationship between the upper and lower respiratory tracts.

Discovery of the novel and potent histamine H1 receptor antagonists for treatment of allergic diseases

Desloratadine, a second-generation histamine H1 receptor antagonist, has established itself as a first-line drug for the treatment of allergic diseases. Despite its effectiveness, desloratadine exhibits an antagonistic effect on muscarinic M3 receptor, which can cause side effects such as dry mouth and urinary retention, ultimately limiting its clinical application. Herein, we describe the discovery of compound Ⅲ-4, a novel H1 receptor antagonist with significant H1 receptor antagonistic activity (IC50 = 24.12 nM) and enhanced selectivity towards peripheral H1 receptor. In particular, Ⅲ-4 exhibits reduced M3 receptor inhibitory potency (IC50 > 10,000 nM) and acceptable hERG inhibitory activity (17.6 ± 2.1 μM) compare with desloratadine. Additionally, Ⅲ-4 exhibits favorable pharmacokinetic properties, as well as in vivo efficacy and safety profiles. All of these reveal that Ⅲ-4 has potential to emerge as a novel H1 receptor antagonist for the treatment of allergic diseases. More importantly, the compound Ⅲ-4 (HY-078020) has recently been granted clinical approval.

Advances and future perspectives of intranasal drug delivery: A scientometric review

Intranasal drug delivery is as a noninvasive and efficient approach extensively utilized for treating the local, central nervous system, and systemic diseases. Despite numerous reviews delving into the application of intranasal drug delivery across biomedical fields, a comprehensive analysis of advancements and future perspectives remains elusive. This review elucidates the research progress of intranasal drug delivery through a scientometric analysis. It scrutinizes several challenges to bolster research in this domain, encompassing a thorough exploration of entry and elimination mechanisms specific to intranasal delivery, the identification of drugs compatible with the nasal cavity, the selection of dosage forms to surmount limited drug-loading capacity and poor solubility, and the identification of diseases amenable to the intranasal delivery strategy. Overall, this review furnishes a perspective aimed at galvanizing future research and development concerning intranasal drug delivery.