Based on the information provided, it appears that Richard is experiencing symptoms consistent with allergic rhinitis, which is an allergic reaction to environmental triggers such as pollen, dust, or pet dander. The symptoms of nasal congestion, sneezing, rhinorrhea, and postnasal drainage are all indicative of this condition.
During the exam, the fact that Richard touched his fingers to the bridge of his nose and complained of minimal improvement from taking Mucinex suggests that his nasal symptoms are bothering him and impacting his quality of life. The pale, boggy nasal mucosa with clear thin secretions and enlarged nasal turbinates further support the diagnosis of allergic rhinitis.
While his throat is mildly erythematous, his lungs are clear, suggesting that his symptoms are limited to his upper respiratory tract.
Based on this exam, it may be appropriate to recommend that Richard consider further evaluation and treatment for allergic rhinitis, such as allergy testing or a trial of nasal corticosteroid spray. In addition, advising him to avoid environmental triggers that may be exacerbating his symptoms could be helpful.