Complete assessment of nails critical for accurate disorder diagnosis

January 31, 2013

The abnormal appearance of the nails is often a clue to systemic illness; unfortunately, most physicians - dermatologists and primary care providers alike - omit nail assessments.

 

New York - The abnormal appearance of the nails is often a clue to systemic illness; unfortunately, most physicians - dermatologists and primary care providers alike - omit nail assessments.

Conducting an assessment of all 20 digits must be part of any complete physical examination, according to nail expert Richard K. Scher, M.D.

Dr. Scher

“Nail disorders are far more than just cosmetic problems,” says Dr. Scher, professor of dermatology, Weill Cornell Medical College, New York. “Abnormal fingernails interfere with many functions of the hand.”

Abnormal toenails can impede walking, exercise and other functions.

Amelanotic melanoma

Melanoma of the nails is more likely to be amelanotic than when in the skin, Dr. Scher says. Therefore, the telltale dyspigmentation is missing.

“You may think it’s an infection, pyogenic granuloma, or a vascular lesion,” he says. “Therefore, amelanotic melanoma is associated with a significant delay in diagnosis.”

If a patient comes in with a history of trauma, ulceration or an atypical nail lesion, clinicians should consider the possibility of melanoma even without abnormal pigmentation, according to Dr. Scher. (Rangwala S, Hunt C, Modi G, et al. Dermatol Online J. 2011:17(6):8).

Dermatologists are using the dermatoscope to assess the nail more often now than they had in the past, Dr. Scher says. Clinicians will diagnose nail melanoma more accurately when using dermoscopy if they assess the nail matrix rather than just the nail bed (Hirata SH, Yamada S, Almeida FA, et al. J Am Acad Dermatol. 2005;53(5):884-886). Assessment of the nail matrix, however, is a surgical procedure that involves retraction of the proximal nail fold, he notes.

If the patient has longitudinal melanonychia that is diagnosed as melanoma in situ, should amputation be considered? Perhaps not, Dr. Scher says.

“There has been a controversy whether melanoma in situ requires amputation, or whether you can just remove all of the nail unit structures and put a graft over the nail site,” he says.

One study involving a review of seven patients’ records and a review of the literature showed that, rather than amputation, wide excision of the nail unit followed by a skin graft is adequate therapy for melanoma in situ and therefore preferred over amputation. (Sureda N, Phan A, Poulalhon N, et al. Br J Dermatol. 2011;165(4):852-858).

When treating squamous cell carcinoma of the nail, dermatologists need to know that Mohs micrographic surgery is the treatment of choice rather than amputation of the digit at the distal joint (Dika E, Piraccini BM, Balestri R, et al. Br J Dermatol. 2012;167(6):1310-1314).

Beyond onychomycosis

When assessing the abnormal nail, dermatologists need to think beyond onychomycosis, Dr. Scher says.

“Although 50 percent of all nail abnormalities are caused by fungus, 50 percent are not,” he says. “There is a tendency to overdiagnose fungal infection and miss the actual diagnosis. Don’t make a snap judgment.”

The differential may need to include neoplasm and nail psoriasis, as well as other conditions that require biopsy for diagnosis,” Dr. Scher suggests.

Age-related nail conditions

Dermatologists need to remember that nails age along with the rest of the body. Because patients live longer than in the past, patients are more likely to be concerned about a worsening appearance when they become a “superior age.”

Aging nails can become dull, less transparent, discolored and ridged. “Ridges are a form of wrinkling in the nails,” he says. They can also thicken and become more difficult to cut.

Nails also grow more slowly as people age. They are thus more susceptible to fungal infections. To make treatment more complicated, adverse effects from systemic antifungals are more likely because older patients often take multiple medications.

Although physicians often frown on the use of nail acrylics, gel and shellacs, Dr. Scher suggests a more relaxed approach: Everything in moderation.

“If the patient is not allergic to the components, these treatments are not problematic,” he says.

Patients who should avoid acrylic nails include those with nail psoriasis or other nail disorders, along with those who have brittle, breakable, splitting nails. Those who indulge in these nail treatments should give their nails a periodic “holiday,” Dr. Scher says. DT