The Dermatologists's Board Review - March 2020

The contents of these questions are taken from the Galderma Pre-Board Webinar. The Pre-Board Webinar is now an online course. For details, go to https://www.galdermausa.com/Our-Commitment/PreBoard-Webinar.aspx.

1. The cyanotic area on the lunula is extremely tender and painful. Only the one finger is involved. Which one of the following is a true statement about this condition?

a) When multiple, the lesions are usually painful
b) When solitary, the lesions are usually tender
c) The condition is poorly circumscribed
d) When multiple, may be inherited as an autosomal recessive trait
e) Removal will not lead to nail dystrophy

2. These nails may be associated with which one of the following:

a) Nasopharyngeal neoplasms
b) Glomerulonephritis
c) Lymphedema
d) Acrylic nail allergy
e) Iliac spines

1. The cyanotic area on the lunula is extremely tender and painful. Only the one finger is involved. Which one of the following is a true statement about this condition?

b) When solitary, the lesions are usually tender
The glomus, or neuromyoarterial, tumor arises from the arterial segment of the cutaneous glomus, the Sucquet-Hoyer canal. The lesions are most frequently skin-colored or slightly dusky blue, firm nodules. The subungual tumor shows a bluish tinge through the translucent nail plate. The tumor is usually extremely tender and painful. The characteristic location is subungual, but it may occur on the fingers and arms, or elsewhere. Multiple glomangiomas can also occur. These usually nontender lesions are generally widely distributed over the body and are inherited as an autosomal dominant trait. Glomus tumors are well-circumscribed, and when they affect the nail matrix, they are likely to cause permanent nail dystrophy after removal. Magnetic resonance imaging and ultrasound are very helpful for identification.

References
Hasselmann D, Meier TO, Amann-Vesti BR, Thalhammer C. Electric blue finger nail [in German]. Praxis (Bern 1994). 2012;101(8):545-547. doi:10.1024/1661-8157/a000899
Glencoglan G, Dereli T, Kazandi AC. Subungual glomus tumor: surgical and histopathologic evaluation. Cutan Ocul Toxicol. 2011;30(1):72-74. doi:10.3109/15569527.2010.521224

2. These nails may be associated with which one of the following:

c) Lymphedema
Yellow nail syndrome is characterized by yellow color, absent cuticles, slow growth, dystrophic shape, Pseudomonas infection, and transverse ridging. Associated with this is lymphedema and chronic lung disease. Allergy to acrylic sculptured nails and renal disease do not produce these changes. Diagnosis is made by the clinical appearance of the nails along with other syndrome stigmata. Glomerulonephritis and iliac spines occur with nail-patella syndrome.

Nasopharyngeal neoplasms are associated with Bazex syndrome or paraneoplastic acrokeratosis. The differential diagnosis of Bazex syndrome includes glucagonoma syndrome, reactive arthritis, chronic mucocutaneous candidiasis, and pustular psoriasis.

References
Siddiq I, Hughes D. Yellow nails, lymphedema and chronic cough: yellow nail syndrome in an eight-year-old girl. Can Respir J. 2012;19(1):35-36. doi:10.1155/2012/464879 
Nanda A, Al-Essa FH, El-Shafei WM, Alsaleh QA. Congenital yellow nail syndrome: a case report and its relationship to nonimmune fetal hydrops. Pediatr Dermatol. 2010;27(5):533-534. doi:10.1111/j.1525-1470.2010.01259.x

Dr McMichael is professor and chair in the department of dermatology at Wake Forest Baptist Health in Winston-Salem, NC.