Image Credit: © dermnetnz.org
In the “Name That Nail” session at the Maui Derm NP+PA Fall 2025 meeting in Nashville, Tennessee, leading expert in nail surgery, Phoebe Rich, MD, gave an overview of several common nail disorders.1 Rich, owner of Phoebe Rich Dermatology and Oregon Dermatology and Research Center in Portland, presented complex case studies in an interactive format, complete with video demonstrations for an audience of physician assistants and nurse practitioners.
Rich began by presenting a series of interactive case studies, starting with the classic habit-tic deformity, highlighting its characteristic large lunula and detached cuticle resulting from chronic self-manipulation. She then detailed the diagnosis of glomus tumors, emphasizing the importance of the “love test”—a simple but effective technique of point tenderness to localize the lesion prior to surgical excision.
The discussion moved to onychopapilloma, a frequently encountered but benign entity presenting as a longitudinal erythronychia with associated subungual hyperkeratosis. Rich explained that while surgical removal is an option, it is not always necessary given the benign nature of the lesion. She also shed light on retronychia, a condition often misdiagnosed as onychomycosis, characterized by proximal ingrowth and stacking of the nail plate. Diagnosis is clinical, and while acute cases may respond to simple avulsion, chronic forms often require more definitive intervention.
The talk then shifted to more critical diagnostic challenges, including the distinction between benign melanonychia and subungual melanoma. Rich stressed the utility of non-invasive tools, such as transillumination and mycological studies, to rule out benign mimics like subungual hemorrhage or black fungal infections before pursuing a biopsy. She also underscored the diagnostic dilemma posed by nail unit squamous cell carcinoma (SCC), the most common nail malignancy.
Rich presented cases that were initially mistaken for common inflammatory or infectious conditions, such as warts, eczema, or psoriasis. She advised that any unresponsive, refractory nail dystrophy warrants a high index of suspicion for malignancy. Rich noted that nail SCCs frequently affect older males, particularly on the dominant hand’s thumb or third digit, and can present with varied morphologies, including verrucous plaques, longitudinal streaks, or a simple paronychia. The gold standard for treatment remains Mohs micrographic surgery, although wide excision is a viable alternative if bone involvement has been ruled out via X-ray.
The final segment of the session covered pincer nails and myxoid cysts. Rich noted that pincer nails can be iatrogenic, sometimes caused by medications like beta-blockers, and that surgical matricectomy with phenol can offer a durable solution. For myxoid cysts, she clarified that their variable presentation—either as a groove or a bulge—is dependent on their relationship to the nail matrix. She also highlighted the diagnostic utility of dermoscopy and explained that while many resolve spontaneously, symptomatic cysts can be managed with aspiration or injections, with referral to a hand surgeon reserved for refractory cases. Rich concluded by highlighting the importance of using X-rays to diagnose bony growths like exostoses, which can also appear as white, painful lesions under the nail.
Stay tuned to Dermatology Times all week for exclusive conference coverage and expert insights from Maui Derm NP+PA Fall.
Reference
1. Rich P. Nail Disorders. Presented at: Maui Derm NP+PA Fall 2025; September 20-23, 2025; Nashville, Tennessee.