What is the management for a patient presenting with an inflamed mole?

Management of an Inflamed Mole

An inflamed mole requires urgent evaluation to rule out infection or malignant transformation, with incision and drainage for abscess formation, topical antimicrobials for superficial infection, and excisional biopsy for any lesion with concerning features that cannot be diagnosed with certainty as benign. 1, 2

Initial Assessment and Risk Stratification

Determine the Nature of Inflammation

• If the mole shows signs of infection (erythema, purulent drainage, warmth, tenderness), obtain a Gram stain and culture of any pus or exudate to guide antimicrobial therapy 1
• If the mole shows signs of malignant change (asymmetry, border irregularity, color variegation, diameter >6mm, evolution), this takes priority over simple infection management 3
• Document the duration of inflammation, rate of change, and associated symptoms such as bleeding, pain, or rapid growth 4

Key Clinical Features to Assess

• Size and appearance: Flat moles with irregular margins, irregular pigmentation, or multiple colors warrant heightened concern 5
• "Ugly duckling" sign: A mole that looks different from the patient's other moles is more likely undergoing malignant change 3
• ABCDE criteria: Asymmetry, Border irregularity, Color unevenness, Diameter ≥6mm, Evolution 3

Management Algorithm

Step 1: Rule Out Abscess or Carbuncle

• If there is fluctuance or a collection of pus, perform incision and drainage as the primary treatment 1
• Consider adjunctive antibiotics only if systemic inflammatory response syndrome (SIRS) is present: temperature >38°C or <36°C, tachycardia >90 bpm, tachypnea >24 breaths/min, or WBC >12,000 or <4,000 cells/µL 1
• Use an antibiotic active against MRSA (such as doxycycline, clindamycin, or trimethoprim-sulfamethoxazole) if SIRS is present or the patient has markedly impaired host defenses 1

Step 2: Manage Superficial Infection Without Abscess

• Apply topical antimicrobial agents (such as mupirocin) to the inflamed area if there is superficial infection without abscess formation 1
• If topical treatment fails after 7-14 days, add systemic broad-spectrum antibiotics 1
• Ensure the infection is not related to underlying structural issues (such as an inflamed epidermoid cyst, which would require incision and drainage) 1

Step 3: Evaluate for Malignancy

• Any pigmented lesion that cannot be diagnosed with certainty as benign should be excised and pathologically examined 2
• This is critical: inflammation alone does not exclude melanoma, and the annual transformation rate of moles increases with age, particularly in men over 60 (approximately 1 in 33,000 per year) 6
• Excisional biopsy is preferred over incisional biopsy when technically feasible 2
• If complete excision is not possible due to size or location, incisional biopsy is acceptable, but definitive radical surgery must be performed within 7-10 days if melanoma is confirmed 2

Step 4: Urgent Referral Criteria

• Refer urgently to a dermatologist or surgeon with expertise in pigmented lesions if the mole has suspicious features: changing shape, color, or size; three or more colors; or irregular borders 5, 4
• Flat moles on sun-exposed areas in older individuals may represent lentigo maligna (melanoma in situ) and require specialist evaluation 5

Common Pitfalls and Caveats

• Do not assume inflammation is purely infectious: Melanoma can present with inflammatory changes, and treating only the infection without biopsy may delay diagnosis of malignancy 3, 2
• Do not perform Gram stain and culture of inflamed epidermoid cysts: These do not require cultures and should be managed with incision and drainage 1
• Avoid incomplete treatment: If antibiotics are started, complete the full course even if symptoms improve, as incomplete treatment can lead to recurrence 7
• Do not use over-the-counter mole removal creams: These can create scarring and eliminate the ability to pathologically examine the lesion, potentially masking melanoma 8
• Do not delay excision in high-risk patients: Those with atypical mole syndrome, family history of melanoma, or more than 50 moles require enhanced surveillance and lower threshold for biopsy 3, 9

Special Considerations

• In elderly patients or those with contraindications to excision, alternative treatments such as radiotherapy, CO2 laser, or cryotherapy may be considered for lentigo maligna, but only after specialist consultation 5
• For patients with diabetes, obesity, or immunosuppression, there is increased risk of infection, and systemic antibiotics may be more appropriate than topical treatment alone 1
• Any mole removed for any reason (cosmetic, functional, or infectious) should always be sent for pathological examination 2