An Unusual Case of Idiopathic Digital Clubbing: Diagnostic Challenges in a Resource-Limited Rural Setting

Abstract

Digital clubbing is a clinical sign characterized by bulbous enlargement of the distal phalanges and is commonly associated with underlying systemic diseases, particularly cardiopulmonary disorders and malignancy. Idiopathic digital clubbing is rare and represents a diagnosis of exclusion. Establishing this diagnosis is especially challenging in rural healthcare settings with limited access to advanced diagnostic modalities. This case report highlights the importance of a structured diagnostic approach and clinical reasoning in identifying idiopathic digital clubbing in a resource-limited rural setting. A 19-year-old male presented with progressive enlargement, thickening, and rounding of the fingers and toes over a three-year period, accompanied by mild to moderate pain and erythema. Physical examination revealed bilateral digital swelling with a positive Schamroth’s sign. Chest radiography, electrocardiography, transthoracic echocardiography, and abdominal ultrasonography showed no abnormalities. Laboratory investigations were within normal limits except for an elevated free thyroxine (FT4) level with a normal thyroid-stimulating hormone (TSH). Thyroid ultrasonography demonstrated normal gland morphology, and there were no clinical features suggestive of Graves’ disease or thyroid acropachy. Radiographs of the extremities revealed minimal periosteal reaction with surrounding soft tissue swelling. Based on systematic exclusion of secondary causes using available clinical and basic investigative tools, the patient was diagnosed with idiopathic digital clubbing. Further advanced investigations could not be performed due to limited diagnostic resources. This case illustrates that idiopathic digital clubbing can be diagnosed through careful exclusion of secondary causes using available clinical and basic diagnostic tools. A structured diagnostic approach and sound clinical reasoning are essential, particularly in rural settings with limited resources, and long-term follow-up is warranted to detect potential underlying systemic diseases.