Paronychia — SAQ

Stem

A 32-year-old dishwasher presents with a 3-month history of boggy, mildly tender swelling of the proximal nail folds of both thumbs with loss of the cuticle, ridging of the nail plate and an episode of acute worsening 2 weeks ago. He reports daily wet-work exposure with kitchen detergents and vegetable juices. Examination shows a swollen, erythematous proximal nail fold on each thumb with absent cuticle and transverse Beau lines on the affected nails; no pus, no vesicles, no pulp tenderness. Blood glucose is 6.8 mmol/L (HbA1c 5.9%); FBC, U&E and LFTs are normal. Skin swab from the fold grows light Candida albicans on CHROMagar.^[1][2]

Questions

a) What is the most likely diagnosis and what clinical features support it? (2 marks)^[1][2]

Diagnosis: Chronic paronychia of both thumbs. Supporting features: insidious 3-month course; boggy, mildly tender proximal nail fold; multi-finger distribution (both thumbs, dominant hand); loss of the cuticle (the hallmark of chronic paronychia); nail-plate ridging and transverse Beau lines (matrix damage from chronic inflammation); recurrent acute flare; daily wet-work exposure (dishwasher + detergents + vegetable juices = central precipitating irritant); positive candida culture (supports, but is a coloniser rather than the primary cause).^[1][2]

b) What investigations would you arrange? (3 marks)

1. Skin swab (MCS + fungal) from the fold — bacterial culture, KOH mount, CHROMagar Candida species identification (already obtained in this case); consider repeat swab if not done.^[1][2]
2. None required as routine beyond the swab; investigations are clinical-driven for chronic paronychia.^[1][2]
3. Screen for predisposing disease in recurrent / refractory cases: fasting glucose / HbA1c (already done — normal), HIV 4th-generation Ag/Ab (high-prevalence populations), ferritin + iron studies (iron deficiency impairs neutrophil oxidative burst), FBC + differential, TFTs.^[1][2]
4. Biopsy to exclude nail-unit squamous cell carcinoma / acrodermatitis continua of Hallopeau — reserved for single-digit chronic disease unresponsive to 6+ months of conservative management.^[1][2]
5. HSV PCR from any vesicles that appear; X-ray distal phalanx if bone pain or systemic signs (exclude osteomyelitis of distal phalanx).^[1][2]

c) Outline your management plan for this patient. (3 marks)^[1][2]

The four-pillar chronic-paronychia ladder:

1. DRY-WORK DIRECTIVES (the foundation): stop wet-work exposure; cotton-lined rubber gloves for all wet tasks; SLS-free (sodium lauryl sulphate-free) hand cleanser; emollient (white soft paraffin, urea-based) after every wash; barrier cream (dimeticone); keep nails short and unpolished; avoid artificial nails.^[1][2]
2. TOPICAL ANTI-INFLAMMATORY: topical tacrolimus 0.1% ointment BD × 6 weeks (steroid-sparing first-line per Rigopoulos 2009 BRJ Dermatol RCT vs betamethasone valerate 0.1% — equivalent efficacy, no atrophy) OR potent topical corticosteroid (clobetasol propionate 0.05% ointment BD × 2-4 weeks) for short-course cover.^[1][2]
3. ANTIFUNGAL / ANTIBACTERIAL ADJUNCT: topical clotrimazole 1% / miconazole 2% cream BD × 4-6 weeks (candidal culture positive); OR oral fluconazole 50 mg OD × 3-6 weeks / 150 mg weekly × 4-8 weeks (low-cost weekly pulse is the Indian / LMIC standard); for bacterial inflammatory component, oral doxycycline 100 mg BD × 6-12 weeks OR minocycline 100 mg BD × 6-12 weeks.^[1][2]
4. SURGICAL (marsupialisation) for refractory disease after 3+ months of conservative management.^[1][2]

Set expectations: nail regrowth takes 3-6 months (fingers) / 12-18 months (toes); chronic paronychia recurs in 30-50% if wet-work exposure is resumed before the cuticle regenerates.^[1][2]

d) What are the key complications and prognostic factors? (2 marks)^[1][2]

Complications: chronic nail dystrophy (ridging, Beau lines, onycholysis, green-brown discoloration); matrix damage and permanent plate deformity; chronic Pseudomonas paronychia (green-nail syndrome) if untreated; secondary acute bacterial paronychia superimposed on chronic paronychia; rarely distal phalanx osteomyelitis in diabetics. Misdiagnoses to avoid: herpetic whitlow (DO NOT incise), felon (different compartment — finger pulp), periungual pyogenic granuloma (drug-induced EGFr / MEK / BTK inhibitors), acrodermatitis continua of Hallopeau (sterile pustules of pustular psoriasis), nail-unit squamous cell carcinoma / melanoma in single-digit disease. Prognostic factors predicting recurrence / refractoriness: persistent wet-work exposure; diabetes mellitus; peripheral vascular disease; Raynaud phenomenon; immunocompromise; drug-induced paronychia (retinoid, EGFr / MEK / BTK inhibitor); iron deficiency; malnutrition; failure to remove the irritant.^[1][2]

References3ShowHide

1. [1]Leggit JC Acute and Chronic Paronychia Am Fam Physician, 2017.PMID 28671378
2. [2]Bahunuthula RK, Thappa DM, Kumari R, et al. Evaluation of role of Candida in patients with chronic paronychia Indian J Dermatol Venereol Leprol, 2015.PMID 26087081
3. [3]Fowler JR, Ilyas AM Epidemiology of adult acute hand infections at an urban medical center J Hand Surg Am, 2013.PMID 23647640