Bone Abstracts

Background: Acroosteolysis is a term used to describe bone resorption of the hands and toes. Typically involving distal phalanges, its causes may be hereditary, inflammatory, traumatic, toxin-mediated or idiopathic non-familial.

Presenting problem: An 11-year old Chinese girl presented to the dermatology clinic with nail resorption of the left index finger for 1 year. She was previously well with no history of connective tissue disorders and no history of frequent trauma to fingers or chemical exposure.

Clinical management: She was referred to the endocrine clinic to exclude metabolic bone disease. Hand X-rays revealed resorption of distal phalanges of the index and middle fingers of both hands (Figure 1). Bone biochemistry was normal (PTH: 3.6 pmol/l, calcium: 2.54 mmol/l, phosphate: 1.4 mmol/l), and inflammatory, autoimmune markers were not elevated. Her father had abnormal toe nails since adolescence and his foot X-ray showed resorption of second and fourth terminal phalanges of the right feet and his lesions seemed to be nonprogressive. With the given history our patient possibly has autosomal dominant hereditary phalangeal acroosteolysis. Reassurance was provided to the family.

Discussion: Acroosteolysis is a well-known consequence of chronic occupational exposure to vinyl chloride. Other causes include frequent trauma as in the case of guitar players and peripheral ischemia caused by frostbite and infectious diseases such as leprosy, meningococcemia, and syphilis. Hyperparathyroidism has been associated with resorption of terminal tufts of phalanges. Acroosteolysis is also linked with several connective tissue diseases. Idiopathic non-familial variant is of unknown etiology and usually affects fingers and is progressive. Hereditary causes of acroosteolysis follow an autosomal dominant or recessive pattern of inheritance and distal phalanges are primarily affected. Dystrophic nails may represent cutaneous manifestation of underlying bone involvement. Consider X-ray imaging in patients with disorders of the nail apparatus.

Disclosure: The authors declared no competing interests.

Figure 1 Hand X-ray showing resorption of distal phalanges of the index and middle fingers of both hands.