What conditions can cause chronic, persistent fingertip or nail‑bed pain and hypersensitivity in a single finger?

Chronic Fingertip and Nail Bed Pain in a Single Digit

The most likely diagnoses for chronic, persistent pain and hypersensitivity localized to one fingertip or nail bed are chronic paronychia (especially with occupational moisture exposure), glomus tumor, or squamous cell carcinoma in situ of the nail unit, with the specific diagnosis depending on associated clinical features. 1, 2, 3

Primary Differential Diagnoses

Chronic Paronychia

• Presents with redness, mild swelling of the nail fold, absence of the cuticle, thickened nail plate with horizontal ridges, and persistent symptoms lasting months 1
• Typically occurs in the context of occupational water exposure or repeated moisture contact 1
• Represents an inflammatory dermatitis rather than primarily infectious process 1, 4
• The nail fold shows erythema and swelling with a gap between the proximal nail fold and nail plate 5
• Pain is present but typically not the severe, paroxysmal type seen with glomus tumors 1, 4

Glomus Tumor

• Classic triad: localized tenderness, severe paroxysmal pain, and cold sensitivity 2
• The appearance of the nail and digit is often completely normal despite severe symptoms 2
• Women are affected more often than men 2
• Clinical suspicion is key to diagnosis, as there is often a delay of many years before correct identification 2
• MRI may be useful for confirmation when clinical suspicion is high 2
• Multifocal tumors are common, and patients may develop complex regional pain syndrome as a complication 2

Squamous Cell Carcinoma In Situ of the Nail Unit

• Can present as hyperkeratotic proliferations, erosions, scaling of the nail fold, periungual swelling, paronychia, or fissure/ulceration of the lateral nail groove 3
• May present with nail dystrophy, onycholysis, or extensive hyperkeratosis of the nail bed 3
• The presence of ulceration, bleeding, or a nodule indicates transformation to invasive carcinoma 3
• Diagnosis is often delayed due to initial misdiagnosis as a benign lesion 3
• The threshold for biopsy should be low if the condition persists despite treatment 3

Diagnostic Algorithm

Initial Clinical Assessment

• Determine if paronychia (nail fold swelling/erythema) is present, which suggests chronic paronychia or Candida infection 1, 5
• Assess for the classic triad of severe paroxysmal pain, localized tenderness, and cold sensitivity, which strongly suggests glomus tumor 2
• Look for ulceration, bleeding, nodule formation, or progressive nail destruction, which raises concern for malignancy 3
• Evaluate occupational history for repeated moisture exposure or chemical irritant contact 1, 4

Examination Priorities

• Examine nail texture: soft and friable suggests infection, hard and brittle suggests non-infectious causes 5, 6
• Check for absence of cuticle and nail fold inflammation characteristic of chronic paronychia 1
• Assess whether the digit appears normal externally despite severe pain (typical of glomus tumor) 2
• Look for hyperkeratotic changes, erosions, or granulation tissue suggesting malignancy 3

Laboratory and Imaging Workup

• If paronychia with nail changes is present, obtain mycological confirmation with KOH preparation and fungal culture before initiating antifungal therapy, as 50% of dystrophic nails are non-fungal 5, 6
• If severe paroxysmal pain with normal appearance is present, obtain MRI to evaluate for glomus tumor 2
• If persistent symptoms despite treatment or concerning features for malignancy, perform biopsy with low threshold for repeat biopsy if initial results are inconclusive 3

Treatment Approach by Diagnosis

For Chronic Paronychia

• Apply mid to high potency topical corticosteroid ointment to the affected nail fold twice daily 1
• Keep hands dry and out of water when possible; wear waterproof gloves with cotton liners when water exposure is unavoidable 1
• Apply moisturizer after hand washing and before wearing gloves 1
• Avoid irritants including harsh soaps, detergents, and extreme water temperatures 1
• Reassess after 2 weeks; consider stronger topical steroids or alternative diagnoses if not improving 1
• Topical antifungals are less effective than corticosteroids for the primary inflammatory process 1
• Antibiotics are only indicated when bacterial superinfection is present with purulent drainage or severe pain 1

For Glomus Tumor

• Surgical excision is the definitive treatment and can be curative 2
• Be aware that local tumor recurrence and metachronous tumors are common 2
• Monitor for development of complex regional pain syndrome as a complication 2

For Squamous Cell Carcinoma In Situ

• Management typically involves local excision, Mohs micrographic surgery, or distal phalanx amputation 3
• Mohs micrographic surgery is preferred for nail apparatus involvement to allow adequate excision while preserving normal tissue and function 3
• A multidisciplinary approach to resection and reconstruction is required 3

Critical Pitfalls to Avoid

• Do not assume fungal infection without laboratory confirmation—treat chronic paronychia as an inflammatory condition first 1, 6
• Do not dismiss severe fingertip pain with normal appearance; maintain high suspicion for glomus tumor, especially in women 2
• Do not delay biopsy when symptoms persist despite appropriate treatment for presumed benign conditions 3
• Avoid prolonged use of topical antibiotics, which can cause allergic contact dermatitis 1
• Do not overlook systemic conditions such as iron deficiency, which can cause nail dystrophy and pain 6
• Recognize that diagnosis of glomus tumors is often delayed by many years due to normal external appearance 2