What is the differential diagnosis for a patient presenting with absent nail cuticles?

Differential Diagnosis for Absent Nail Cuticle

Chronic paronychia is the primary diagnosis to consider when a patient presents with absent nail cuticles, as loss of the cuticle is a hallmark feature of this condition, representing chronic inflammation and irritant contact dermatitis of the nail fold rather than an infectious process. 1

Primary Differential Considerations

Chronic Paronychia (Most Common)

• Absence of the cuticle is pathognomonic for chronic paronychia, typically accompanied by redness, mild swelling of the nail fold, and thickened nail plate with horizontal ridges 1
• Symptoms persist for at least 6 weeks and represent an irritant contact dermatitis rather than primarily infectious etiology 2
• Commonly affects individuals with wet occupations including housekeepers, dishwashers, bartenders, florists, bakers, and swimmers 2
• Up to 25% of cases have secondary bacterial or mycological superinfection 2

Squamous Cell Carcinoma In Situ of the Nail Unit

• Can present with whitish cuticle or periungual changes that may mimic or progress to cuticle loss 3
• May present as hyperkeratotic proliferations, erosions or scaling of the nail fold, periungual swelling, or fissure/ulceration of the lateral nail groove 3
• Diagnosis tends to be delayed due to initial misdiagnosis as benign lesions; maintain low threshold for biopsy if condition persists 3
• HPV16 has been detected in periungual SCC in situ 3

Systemic Connective Tissue Diseases

• Systemic lupus erythematosus and dermatomyositis can cause periungual changes with cuticle abnormalities or loss
• Typically accompanied by other systemic manifestations and nail fold capillary changes

Psoriatic Nail Disease

• Can cause nail fold inflammation and cuticle disruption
• Usually presents with additional nail findings including pitting, onycholysis, and oil drop discoloration

Critical Clinical Pitfalls

Do not assume all absent cuticles represent simple infection requiring antibiotics - chronic paronychia is primarily an inflammatory/irritant dermatitis condition, and antibiotics are only indicated when bacterial superinfection is present with purulent drainage or severe pain 1

Avoid topical antibiotics as first-line treatment - the American Contact Dermatitis Society specifically warns these can cause allergic contact dermatitis and are less effective than corticosteroids for the primary inflammatory process 1

Consider malignancy if unilateral, persistent, or treatment-refractory - maintain low threshold for biopsy, as SCC in situ diagnosis is frequently delayed and can be misinterpreted even on histopathology 3

Diagnostic Approach Algorithm

1. Duration assessment: Symptoms >6 weeks strongly suggest chronic paronychia rather than acute infection 2

2. Occupational/exposure history: Identify chronic moisture exposure, chemical contact, or repetitive trauma 2, 1

3. Unilateral vs bilateral: Bilateral involvement with occupational exposure favors chronic paronychia; unilateral persistent lesions raise concern for malignancy 3, 1

4. Associated findings:

   • Thickened nail plate with horizontal ridges → chronic paronychia 1
   • Whitish cuticle, ulceration, nodule, or bleeding → consider SCC in situ 3
   • Systemic symptoms or other skin/joint findings → consider connective tissue disease

5. Culture consideration: Reserve for purulent drainage or suspected superinfection; not routinely needed for chronic paronychia 2, 1

6. Biopsy threshold: Perform if unilateral, persistent despite appropriate treatment, or any concerning features for malignancy 3