<unk>  is a medical condition defined by the concurrence of large, rounded fingernails and bronchiectasis. Despite the visual similarity between the two conditions,<unk>  and clubbed fingernails are opposites.<unk>  results from atrophy to the nail bed, whereas clubbed fingernails results from a bulbous, hypertrophic growth of soft tissue. The concurrence of the syndrome and bronchiectasis is well-established, however the exact causes of the deformity remains unknown. The syndrome has been observed affecting both the hands and larger toenails. The link between<unk>  and bronchiectasis is present within the first description of the syndrome. The patient, a 37 year-old-woman admitted to hospital, recounts first noticing a "persistent dystrophy" of her fingernails at age five, this occurring one year after suffering from severe whooping cough followed by pneumonia. A 2013 Clinics in Dermatology publication defines the disease as "nails which resemble clubbed nails with the exception of the distal nail bed, which is atrophic rather than hypertrophied and bulbous." Cause and diagnosis At present, the specific cause of<unk>  is unknown. American doctors Chalmers E. Cornelius and Walter B.<unk> ey first characterized the morphogenesis of the condition in a 1967 Archives of Dermatology publication, stating: "this disorder can be explained by the production of a curved nail by a normal nail matrix which grows out as a<unk>  to thus form a roof over the atrophic process of the more acral portions of the digit." This description of how the nail "grows out as a<unk> " to cover the atrophied nail bed is where the syndrome takes its name. Diagnosis of<unk>  is preformed by x-ray of the patient's distal phalanges. A side view of a fingertip affected by<unk>  will reveal an air space between the nail and nail bed. The first description of the syndrome contains diagnosis by removal of the nail plate.<unk>  is commonly bilateral due to its concurrence with pulmonary, cardiac, and gastrointestinal diseases. The syndrome can be slow to develop, occurring without the patient's notice for multiple months.
Shell nail syndrome
Elejalde syndrome
Green nail syndrome
Scimitar syndrome
Yellow nail syndrome
Blue toe syndrome
Freiberg disease
Alien hand syndrome