Do You Recognize These Nail Disorders?

Case 1:

During a routine skin examination,periungual erythema and increasedcurvature of the nail plate are notedin a 78-year-old man. The patient hasemphysema and a smoking historyof more than 50 pack-years. Currently,he requires oxygen support forregular daily activity.What do you suspect is thecause of the nail deformity?

Case 1:Clubbing of the nails can

be congenital or acquired. Thelatter form is associated with bothneoplastic and inflammatory

pulmonarydiseases

in most patientsand with cardiovascular abnormalitiesin nearly all the rest. Other systemicillnesses--such as inflammatorybowel disease, HIV infection,cirrhosis, hypertrophic osteoarthropathy,and hyperthyroidism--are rare causes of clubbing.In affected patients, the distaldigits are enlarged and swollen.The nail plate is curved, and theangle between the proximal nailfold and the nail plate (Lovibondangle) is greater than 180 degrees.To confirm the increased angle,position the nails of both indexfingers close together. In patientswithout clubbing, there is a diamond-shaped space between thenails. This space is markedly decreasedor completely absent in patientswith clubbing.There is no effective treatment.Management of the underlying systemicillness may not correct thenail abnormalities.

Case 2:

A 43-year-old man with hepatitis Cvirus infection and cirrhosis complainsof dry, itchy skin. He also haspaired, transverse white bands onall his fingernails.To what do you attribute thenail discoloration?

Case 2:

The white bands on this patient'snails are

Muehrcke lines--

arelatively uncommon finding associatedwith a

low albumin level

and

cirrhosis.

The white bands are horizontallypaired, separated by areas ofnormal nail color, and arranged parallelto the lunula. Muehrcke linesare a good clue to the presence ofhypoalbuminemia; this patient's albuminlevel was 2.1 g/dL.The differential diagnosis includesleukonychia (congenital andacquired) and Mees lines (causedby arsenic poisoning). These abnormalitiesare in the nail plate, whileMuehrcke lines represent edema inthe nail bed.Treatment of the nails is unnecessary. Bear in mind that ameliorationof the underlying systemic illness may not change the nail color.This patient's low albumin level is chronic, and he is being monitoredclosely by a hepatologist.

Case 3:

For 2 years, a 55-year-old man hashad gradual thickening and yellowdiscoloration of his toenails. Hereports no pain or pruritus. He isotherwise healthy and has no significantmedical history.What is this condition, and howwould you treat it?

Case 3:

This patient has

onychomycosis;

microscopic examination of apotassium hydroxide preparation of nail scrapings confirmed the diagnosis.This fungal infection of the nail plate is relatively common in middle-agedand elderly patients. The most common causative fungal organism is

Trichophytonrubrum.

Other possible causative organisms include other dermatophytes,such as

Trichophyton mentagrophytes,

as well as saprophytes,such as

Aspergillus

and

Fusarium

species.Topical antifungal treatment is often ineffective because the medicationcannot penetrate the nail plate. Oral terbinafine is the treatment of choice.A 6-week course is required for fingernail infections; a 12-week course isneeded for toenail infections. Although terbinafine is relatively safe, it doespose a low risk of hepatitis. Hence, a baseline liver function test is needed,especially for patients with a prior or a current history of liver disease.This patient responded well to a 12-week course of oral terbinafine. Formaintenance, he was instructed to apply terbinafine cream to his feet oncea week.