## 3 Results
### Allergic Rhinities
#### 3.2.2 Treatment of Allergic Rhinitis  
AR management includes patient education, allergen avoidance, pharmacotherapy, immunotherapy, and biologics. It is essential to explain to the patient about their disease and how to take their treatments. The first step is to avoid exposure to the allergen. However, if the symptoms persist, the first line of treatment is drug therapy. Immunotherapy is recommended when the disease is not controlled with the usual drugs. In addition, in recent years, biologics have emerged as a novel therapeutic option with promising results [175; 176; 177; 178] (Figure 3). Typical AR drugs include AHs, GCs, and leukotriene receptor antagonists. Second-generation oral antihistamines are the first line of pharmacological treatment, as well as intranasal corticosteroids (INCs), which have demonstrated even greater efficacy than AHs. [179]. Intranasal combination therapies with AHs and GCs, such as azelastine hydrochloride/fluticasone propionate (AZE/FP), are also recommended [180]. Antihistamines bind to the histamine H1 receptor and block its action. First-generation of oral antihistamines (OAHs), such as diphenhydramine or chlorpheniramine, have been widely used in the clinic. However, due to their adverse effects, they are no longer supported for AR [181]. Their main secondary effect is sedation as they cross the blood-brain barrier causing drowsiness and fatigue, among other symptoms [182]. Therefore, the use of new-generation AHs (such as desloratadine, loratadine, cetriarine, levocetriarine and rupatadine, fexofenadine, and bilastine) is strongly recommended. These have been shown to be safer than the previous ones, maintaining the same efficacy without the sedative effect [181; 183]. Intranasal antihistamines (INAHs) improve the effect of oral antihistamines at the nasal mucosa [184; 185]. Moreover, they are more effective in controlling local symptoms, such as nasal congestion [186; 187]. In addition, they act faster than OAHs and reduce potentially systemic effects [187]. They are recommended as first-line treatment for seasonal AR (SAR) [122]. The two INAHs approved for the management of SAR are azelastine and adoptadine. Both have demonstrated similar efficacy [188]. They differ in that azelastine inhibits both H1 and H2 receptors, while dopatadine only inhibits H1. INCs (becomenthasone, budesonide, ciclesonide, fluticasone propionate, fluticasone furoate, montasone furoate, and triacnionolone acetonide) have a local anti-inflammatory effect by preventing the recruitment of immune cells into the nasal mucosa. They are indicated as first-line treatment in patients with moderate or persistent symptoms [180]. In addition, they have the advantage of having no systemic adverse effects [189; 190]. INCs have demonstrated efficacy in controlling the main symptoms of AR: nasal congestion, itching, rhinorrhea, and sneezing [191; 192]. INCs have been described to be more effective than AHs for nasal congestion [179]. OCs are not used as a routine treatment for rhinitis, because their adverse effects exceed the potential benefits [193]. A short course, only for a few days, with oral corticosteroids, can be indicated in patients with severe symptoms that do not respond to other drugs [194]. A novel formulation combines azelastine hydrochloride (AZE) and fluticasone propionate (FP) in a single nasal spray. This combined therapy has proved to be faster [195] and more effective than both drugs taken individually. [196; 197]. One of the advantages is that it increases adherence to treatment by administering both drugs at the same time. In addition, the drugs are more homogeneously distributed in the nasal mucosa than if AZE and FP sprays were used sequentially [198]. It is recommended for the initial treatment of moderate to severe nasal symptoms of SAR [180], as well as for patients with both seasonal and perennial AR who do not respond to monotherapy [122].