THE CASE
A 75-year-old man sought care from his primary care physician because his “fingernails and toenails [were] all falling off.” He did not feel ill and had no other complaints. His vital signs were unremarkable. He had no history of malignancies, chronic skin conditions, or systemic diseases. His fingernails and toenails were discolored and lifting from the proximal end of his nail beds (FIGURE). One of his great toenails had already fallen off, 1 thumb nail was minimally attached with the cuticle, and the rest of his nails were loose and in the process of separating from their nail beds. There was no nail pitting, rash, or joint swelling and tenderness.
The patient reported that while on vacation in Hawaii 3 weeks earlier, he had sought care at an urgent care clinic for a painless rash on his hands and the soles of his feet. At that time, he did not feel ill or have mouth ulcers, penile discharge, or arthralgia. There had been no recent changes to his prescription medications, which included finasteride, terazosin, omeprazole, and an albuterol inhaler. He denied taking over-the-counter medications or supplements.
The physical exam at the urgent care had revealed multiple blotchy, dark, 0.5- to 1-cm nonpruritic lesions that were desquamating. No oral lesions were seen. He had been given a diagnosis of hand-foot-mouth disease (HFMD) and reassured that it would resolve on its own in about 10 days.
THE DIAGNOSIS
Several possible diagnoses for nail disorders came to mind with this patient, including onychomycosis, onychoschizia, onycholysis, and onychomadesis.
Onychomycosis is a chronic fungal infection of the nail that affects toenails more often than fingernails.1 The most common form is distal subungual onychomycosis, which begins distally and slowly migrates proximally through the nail matrix.1 Often onychomycosis affects only a few nails unless the patient is elderly or has comorbid conditions, and the nails rarely separate from the nail bed.
Onychoschizia involves lamellar splitting and peeling of the dorsal surface of the nail plate.2 Usually white discolorations appear on the distal edges of the nail.3 It is more common in women than in men and is often caused by nail dehydration from repeated excessive immersion in water with detergents or recurrent application of nail polish.2 However, the nails do not separate from the nail bed, and usually only the fingernails are involved.
Onycholysis is a nail attachment disorder in which the nail plate distally separates from the nail bed. Areas of separation will appear white or yellow. There are many etiologies for onycholysis, including trauma, psoriasis, fungal infection, and contact irritant reactions.3 It also can be caused by medications and thyroid disease.3,4
Continue to: Onychomadesis