Management of Painful Annular Lesions Without Systemic Infection
In a patient with painful annular lesions, no fever, and negative CRP, the primary diagnostic considerations are non-infectious inflammatory dermatoses, particularly granuloma annulare, chronic recurrent annular neutrophilic dermatosis (CRAND), or other figurate erythemas, rather than infectious etiologies.
Initial Clinical Assessment
The absence of fever and negative CRP effectively rules out significant bacterial infection or systemic inflammatory processes that would require urgent antimicrobial therapy 1. This clinical picture is inconsistent with conditions requiring immediate intervention such as:
- Cellulitis or soft tissue infection - which typically presents with elevated CRP (>50 mg/L) and systemic signs 1
- Systemic inflammatory conditions - which would demonstrate CRP elevation and potentially other markers of SIRS 1
Diagnostic Approach
Key Physical Examination Features to Document
Examine the lesions for specific characteristics that guide diagnosis 2, 3:
- Lesion morphology: Raised borders with central clearing versus flat patches
- Scale presence: Trailing scale suggests erythema annulare centrifugum; lack of scale points toward granuloma annulare 4
- Color: Flesh-colored to erythematous papules (granuloma annulare) versus livid or targetoid appearance (other figurate erythemas) 5, 3
- Distribution: Localized to dorsal hands/feet versus disseminated 5
- Pain characteristics: True pain is unusual in most benign annular dermatoses and warrants broader consideration 6
Diagnostic Testing Algorithm
Potassium hydroxide (KOH) examination - First-line test to exclude tinea corporis, which is the most common cause of annular lesions 2, 4
Skin biopsy - Indicated when KOH is negative and diagnosis remains unclear 5, 4:
- Granuloma annulare shows characteristic palisading granulomas
- CRAND demonstrates neutrophilic infiltrate similar to Sweet's syndrome 6
Additional laboratory evaluation - Only if clinical features suggest systemic disease 3:
Management Strategy
For Localized Granuloma Annulare (Most Likely Diagnosis)
Reassurance is the primary intervention, as localized disease is self-limited and resolves spontaneously within 1-2 years in most cases 5.
If treatment is desired for cosmetic reasons 5:
- Intralesional corticosteroids (triamcinolone 5-10 mg/mL) for localized lesions
- Liquid nitrogen cryotherapy for small lesions
- Topical corticosteroids under occlusion for limited disease
For Disseminated or Persistent Disease
If lesions are widespread or fail to resolve after 2 years, consider dermatology referral for systemic therapy 5:
- Dapsone, antimalarials (hydroxychloroquine), or other immunomodulatory agents
- These require monitoring for potential toxicities
For CRAND (If Biopsy Confirms)
Colchicine 1 mg daily has demonstrated efficacy in preventing recurrences, with one case showing no relapses over 10 years of observation 6. Hydroxychloroquine was ineffective in the reported cases 6.
Critical Pitfalls to Avoid
- Do not initiate antibiotics based solely on annular morphology without evidence of infection (elevated CRP, fever, or purulence) 1
- Do not assume all annular lesions are fungal - obtain KOH confirmation before treating with antifungals 2, 4
- Do not overlook erythema migrans - if there is history of tick exposure and expanding annular lesion, treat empirically for Lyme disease even with negative CRP 3
- Do not pursue extensive systemic workup in the absence of constitutional symptoms or laboratory abnormalities 6, 5
When to Escalate Care
Dermatology consultation is warranted if 5, 3:
- Diagnosis remains uncertain after KOH and initial evaluation
- Disseminated disease requiring systemic therapy
- Lesions persist beyond 2 years despite conservative management
- Features suggest systemic disease (lupus, sarcoidosis, vasculitis)