APMLE Dermatology and Nail Disorders 3

Question 1

Pitted keratolysis presents with malodorous, punched-out erosions on the plantar surface. Which bacteria is the primary causative agent?

Accepted Answer

Kytococcus sedentarius (Micrococcus sedentarius)

Answer

Staphylococcus aureus

Answer

Pseudomonas aeruginosa

Answer

Group A Streptococcus

Question 2

A patient presents with a tender, pulsatile, bluish nodule under the nail of the hallux that causes severe pain with cold exposure. What is the most likely diagnosis?

Accepted Answer

Glomus tumor

Answer

Subungual exostosis

Answer

Blue nevus

Answer

Melanoma in situ

Question 3

Erythrasma affecting the web spaces of the foot is caused by which organism and best treated with which antibiotic?

Accepted Answer

Corynebacterium minutissimum; erythromycin

Answer

Candida albicans; fluconazole

Answer

Trichophyton interdigitale; terbinafine

Answer

Staphylococcus epidermidis; dicloxacillin

Question 4

Which nail disorder is characterized by excessive lateral curvature of the nail plate that pinches the soft tissue without penetrating it, often causing pain and onycholysis?

Accepted Answer

Pincer nail (involuted nail)

Answer

Onychocryptosis

Answer

Onychomadesis

Answer

Clubbing

Question 5

Beau's lines (transverse depressions across the nail plate) occur as a result of:

Accepted Answer

Temporary arrest of nail matrix cell proliferation

Answer

Fungal invasion of the nail matrix

Answer

Repeated trauma to the nail fold

Answer

Subungual bacterial infection

Question 6

Which of the following accurately describes the 'nail-patella syndrome' finding relevant to podiatric practice?

Accepted Answer

Absence of the thumbnail and hypoplastic toenails with associated renal dysplasia

Answer

Onychogryphosis with absent patellae and clubfoot deformity

Answer

Nail pitting with lateral luxation of the patella and pes planus

Answer

Koilonychia (spoon nails) with patella maltracking

Question 7

A diabetic patient presents with a macerated, white hyperkeratotic plaque in the third web space. KOH prep reveals hyphae. Which topical antifungal is most appropriate as initial therapy?

Accepted Answer

Clotrimazole 1% cream applied twice daily

Answer

Ciclopirox 8% nail lacquer

Answer

Econazole 1% cream with occlusion

Answer

Nystatin powder applied daily