Yellow Nail Syndrome Associated With a Dental Abscess: A Case Report.

Yellow nail syndrome (YNS) is a rare disorder marked by a triad of symptoms: lymphedema, yellow discolored nails, and respiratory manifestations. It is often associated with conditions such as chronic cough, bronchiectasis, pleural effusion, and chronic rhinosinusitis. Although its precise etiology remains elusive, it is believed that impaired lymphatic drainage plays a central role in its pathogenesis. YNS predominantly affects individuals over the age of 50, and there is no definitive treatment, though some cases may achieve partial or spontaneous remission. In this report, we present the case of a man in his mid-30s with a one-year history of persistent cough, sinus congestion, yellow deformed nails, and lymphedema. Extensive investigations, including imaging and pulmonary function tests, revealed no significant pulmonary abnormalities. The patient underwent multiple rounds of treatments, including antibiotics, antifungal therapy, inhaled and systemic corticosteroids, and nail care regimens, all of which proved ineffective in resolving his symptoms. Further evaluation, including dental imaging, uncovered an odontogenic abscess. After the infected tooth was extracted, the patient experienced a significant and gradual resolution of his symptoms, including yellow nail discoloration and sinus issues. This case highlights the importance of considering secondary causes, such as dental infections, in the workup of patients with YNS, particularly when standard treatments fail to produce improvements. To our knowledge, this is the first reported case identifying a tooth abscess as the potential cause of YNS. YNS has been linked to several systemic conditions, including autoimmune disorders, thyroid dysfunction, nephrotic syndrome, and malignancies, but an association with dental abscesses has not been previously documented. This case underscores the critical need for a thorough evaluation of potential contributory factors in YNS, especially in younger patients who do not fit the typical demographic profile. It also emphasizes the importance of timely management of secondary infections, which can lead to significant clinical improvement in such cases. By illustrating a rare presentation of YNS, this case provides further insight into the syndrome's complexity and the potential role of odontogenic infections in its development.