What Are the Top Skin Conditions Podiatrists Encounter?

In the office, podiatrists see lower extremity dermatological issues essentially hourly. This blog, adapted from my recent cover story found here. highlights just a few of the most common podiatric skin conditions in no specific order. Make sure to read the full story for all of the details and the full list.

Plantar Verruca

Clinically, plantar warts are well-circumscribed lesions with overlying hyperkeratosis seen in children and adults. Human papillomavirus (HPV), a double-stranded DNA virus, is responsible for plantar verrucae. HPV needs both an epidermal abrasion and a transiently impaired immune system to inoculate a keratinocyte in the basal layer of the epidermis.¹ 

Thirty percent of warts may clear spontaneously, but those that do not often become cosmetically unappealing, painful, and irritating to the patient.¹ There are several treatments for plantar verrucae; however, none are specific to directly damaging HPV. They include non-surgical and surgical methods, such as the use of keratolytic agents (salicylic acid), cryotherapy (liquid nitrogen), laser (pulsed dye and CO₂), excision, bleomycin injections, folk remedies, and the latest FDA-approved microwave device.

Ingrown Nails: Onychocryptosis and Paronychia

Ingrown toenails often cause significant pain and disability to the patient.² Great toenails are most affected, but any toenail can become ingrown on either the lateral or medial nail border, or both. They present as painful onychocryptosis (incurvation of the lateral edge of the nail plate) with or without lateral nail fold edema or redness. Ingrown toenails may progress to paronychia with pain, lateral nail fold edema, focal erythema, drainage, granulation tissue, and possible hypertrophy of the periungual tissue. Conservative treatment methods include the “slant back” procedure and taping of the lateral nail fold to encourage the skin not to encroach the nail. However, these methods require patience and time on the patient’s part.²

For those patients in whom conservative therapy has failed or whose presentation is too severe for a non-surgical intervention, a partial nail avulsion of the affected side may become indicated. This procedure aims to decrease the width of the nail plate of the offending nail border to relieve pain and pressure. In patients where ingrown nails become a chronic scenario, the procedure can include removal/destruction of the nail matrix, either surgically or chemically, to cause long-term narrowing of the nail plate.²

Onychomycosis

Onychomycosis is a common superficial fungal infection of the nails leading to discoloration, nail plate thickening, and onycholysis. Mycotic nail disease is the most common nail pathology worldwide, reaching all cultures and ethnicities. Onychomycosis is increasing, accounting for up to 90 percent of toenail and at least 50 percent of fingernail infections.³ The most common fungal culprits in the United States are the dermatophytes Trichophyton rubrum and Trichophyton mentagrophytes.⁴ Non-dermatophyte molds and yeasts also play a role with varying frequency.^5,6 Because the initial diagnosis depends on the nail’s appearance and other nail diseases may visually mimic onychomycosis, lab tests assist in obtaining a definitive diagnosis. Visual nail plate changes help classify onychomycosis.^5,6

In the last several years, novel treatments of onychomycosis have arisen. FDA-approved medications include oral antifungals (terbinafine and itraconazole), topical antifungals (efinaconazole, tavaborole, and ciclopirox), and laser therapy (approved to temporarily improve the nail’s visual appearance). No matter the treatment, the toenail only grows 1 to 2 mm per month, and treatment can take anywhere from 12 to 18 months due to the slow turnover from the cuticle to the distal tip of the nail.

Dr. Vlahovic is a Clinical Professor in the Department of Podiatric Medicine at the Temple University School of Podiatric Medicine in Philadelphia.

1. Sterling JC, Handfield-Jones S, Hudson PM. Guidelines for management of cutaneous warts. Br J Dermatol. 2001;144(1):4-11.

2. Vlahovic TC. (2020) Permanent ingrown toenails: chemical and surgical procedures. In: Tower DE. (ed) Evidence-Based Podiatry. Springer, Cham. https://doi.org/10.1007/978-3-030-50853-1_1

3. Ghannoum MA, Hajjeh RA, Scher R, et al. A large-scale North American study of fungal isolates from nails: the frequency of onychomycosis, fungal distribution, and antifungal susceptibility patterns. J Am Acad Dermatol. 2000;43(4):641–648.

4. Thomas J, Jacobson GA, Narkowicz CK, et al. Toenail onychomycosis: an important global disease burden. J Clin Pharm Ther. 2010;35(5):497–519.

5. Zaias N. Onychomycosis. Dermatol Clin. 1985;3(3):445–460.

6. Westerberg DP, Yoyack MJ. Onychomycosis: current trends in diagnosis and treatment. Am Fam Physician. 2013;88(11):762–770.