What is the diagnosis and management plan for a relatively healthy individual with no significant past medical history, presenting with episodes of fatigue and a notable oval-shaped skin lesion, approximately 6 cm by 3 cm, with multiple colors?

Diagnosis and Management of Multicolored Skin Lesion with Fatigue

This patient requires urgent dermatology referral for suspected melanoma given the large (6 cm × 3 cm), multicolored, oval skin lesion, which meets clinical criteria for malignancy until proven otherwise. 1

Primary Concern: The Skin Lesion

Why Melanoma Must Be Ruled Out First

• A noncalcified solitary lesion that cannot be proven stable for at least 2 years should be considered potentially malignant. 1
• The described lesion (6 cm × 3 cm, oval, multiple colors) raises immediate concern for melanoma based on the "ABCDE" criteria: Asymmetry, Border irregularity, Color variation, Diameter >6mm, and Evolution. 1
• Dermatology referral should not be delayed while awaiting laboratory results for fatigue workup, as early excision of melanoma directly impacts mortality. 1

Alternative Diagnoses to Consider

While melanoma is the primary concern, the differential includes:

• Lyme disease (erythema migrans): However, erythema migrans typically expands over days to weeks, must be ≥5 cm, and appears as a round/oval erythematous lesion—but is usually homogeneously red or has central clearing, not "multiple colors." 1
• Pyoderma gangrenosum: Presents as pustules progressing to deep ulcerations with violaceous edges, not multicolored oval lesions. 1
• Fungal infections: Show peripheral scaling and satellite lesions, lacking the multicolored appearance described. 2, 3

The "multiple colors" descriptor is the critical red flag that distinguishes this from benign inflammatory conditions and points toward melanoma. 1

Secondary Concern: Episodic Fatigue

Appropriate Initial Workup

The planned investigations (CBC, ferritin, thyroid function, liver function, inflammatory markers) are reasonable first steps. 4

However, the episodic pattern of fatigue ("feeling unwell for an hour or so at night, then symptoms resolve") warrants cardiovascular and neurological evaluation rather than assuming a metabolic cause. 5

Critical Distinction in Fatigue Patterns

• Episodic weakness with complete resolution suggests transient ischemic attacks, cardiac insufficiency, arrhythmias, or orthostatic hypotension rather than chronic medical conditions like anemia or hypothyroidism. 5
• If inflammatory markers return normal, this effectively rules out systemic inflammatory conditions. 5
• Consider ECG, echocardiogram, and Holter monitoring if the episodic pattern persists after initial metabolic workup is negative. 5

If Initial Workup Is Negative

• Most medical causes of fatigue are evident on initial presentation with history, physical examination, and screening labs. 4
• If no medical cause is identified, further "fishing expeditions" are fruitless—consider psychiatric causes (depression, anxiety) based on history, not as diagnosis of exclusion. 4
• Protracted fatigue following an acute illness can represent a deconditioned state requiring physical therapy referral for reconditioning protocols. 1

Clinical Algorithm

1. Immediate action: Expedite dermatology referral for skin lesion evaluation and likely biopsy. 1

2. Parallel workup for fatigue:

   • Complete planned laboratory investigations (CBC, ferritin, TSH, LFTs, ESR/CRP). 5, 4
   • If episodic pattern continues, add cardiovascular evaluation (ECG, echo, Holter). 5
   • Review all medications for potential contributors. 5

3. If skin lesion is benign and labs negative:

   • Reassess fatigue pattern—is it truly episodic or chronic? 5, 4
   • Consider psychiatric evaluation if history suggests mood disorder. 4
   • Refer to physical therapy if deconditioned. 1

Critical Pitfall to Avoid

Do not allow the fatigue workup to delay evaluation of the skin lesion. The multicolored appearance of a 6 cm lesion represents a potential life-threatening condition requiring immediate specialist assessment, while fatigue—though concerning—is unlikely to represent an acute threat in an otherwise healthy individual. 1