Yellow Nail Syndrome (YNS) is a rare clinical syndrome characterized by a triad of thickened, yellow nails, primary lymphedema and respiratory manifestations. The complete triad may not present simultaneously with all three manifestations reported in only 27-60% of patients. While the etiology is unclear, the proposed causes include microvasculopathy with protein leakage or various anatomic or dysfunctional lymphatic drainage/transport abnormalities. We present a case of YNS in a patient with a history of chronic sinusitis, ulcerative colitis, sclerosing cholangitis and liver transplant with IgM immunodeficiency after presenting with lymphedema, acute-onset yellow nails and recurrent bronchiectasis/chronic cough. Case: A 58-year-old male presented with a chronic, productive cough and recurrent chronic sinusitis. His extensive past medical history included partial lung lobectomy/nodulectomy, ulcerative colitis with colectomy and resulting sclerosing cholangitis complicated by the development of cirrhosis with liver transplantation. He was maintained on immunosuppression with tacrolimus and noted immunodeficiency with confirmed low levels of IgM. Over the previous 12 months, he had been on several courses of rotating antibiotics, oral steroids, and nebulizers for infectious concerns. Admission CT findings demonstrated bronchiectasis and chronic frontal/maxillary sinusitis. Bronchoscopy revealed a negative infectious workup. During his recurrent pulmonary flare, the patient began demonstrating worsening bilateral lower extremity edema suspicious for new-onset lymphedema. Physical exam demonstrated acutely developed thickened, yellowish nails on all of his fingernails and toenails with proximal to distal spread. Itraconazole was initiated with mild improvement in his nails. Additionally, ENT referral resulted in bilateral total ethmoidectomy/sphenoidotomy and bilateral frontal sinusotomy due to severe, chronic sinusitis. The patient was placed on vitamin E 400 units daily for his yellow nails with significant improvement. Discussion: YNS has been linked to a variety of underlying diseases, including malignancy, immunodeficiency, and autoimmune disease. More recent studies identify exposure to titanium (teeth crowns, joint implants, sunscreen) as a risk factor. It remains a diagnosis of exclusion with an estimated prevalence of less than 1/1,000,000 with fewer than 400 cases reported. While the triad of lymphedema, yellow nails and pleural effusion are most common, only two criteria are required for diagnosis. Additionally, bronchiectasis and chronic sinusitis are both commonly associated conditions with YNS as noted in our patient. The gold standard of treatment is vitamin E, itraconazole and improved control of respiratory manifestations. Alternative treatments have been largely aimed at resolving the underlying disease, such as immunodeficiency or malignancy.