What is the best course of action for a 49-year-old male patient with a history of chest pain, currently on Lamictal (lamotrigine) 25mg, with a new skin lesion, and recent changes to his medication regimen?

Management of Chest Pain with Recent Medication Changes and New Skin Lesion

The chest pain in this patient is most likely non-cardiac in origin, related to psychological stress from segregation and possibly lamotrigine initiation, but the warm, hardened skin lesion on the inner thigh requires immediate evaluation for cellulitis or abscess, which takes priority over the resolved chest pain. 1, 2

Immediate Assessment of the Skin Lesion

The warm, hardened area on the left inner thigh described as a "spider bite" requires urgent evaluation for bacterial skin infection, which can progress rapidly in correctional settings. 1

• Examine the lesion for size, erythema, fluctuance, lymphangitic streaking, and measure the area of induration 1
• Check vital signs including temperature to assess for systemic infection 2
• Palpate regional lymph nodes (inguinal) for lymphadenopathy 1
• If there is fluctuance, incision and drainage may be required; if there is significant surrounding cellulitis (>5 cm erythema), systemic antibiotics are indicated 1
• Document the exact size and characteristics for monitoring progression 2

Chest Pain Risk Stratification

The chest pain characteristics strongly suggest non-cardiac etiology: sharp quality, ability to localize precisely, radiation pattern that replaces (rather than accompanies) chest discomfort, temporal association with psychological stressor, and complete resolution after medication adjustment. 1, 3

Features Favoring Non-Cardiac Origin:

• Sharp, squeezing quality that the patient can pinpoint exactly suggests musculoskeletal or anxiety-related pain 3
• Pain that disappears from chest when it moves to shoulder (rather than radiating while chest pain persists) is atypical for cardiac ischemia 3
• Temporal relationship to segregation placement indicates stress/anxiety as trigger 3
• Complete resolution after lithium discontinuation and lamotrigine initiation suggests the pain was related to medication side effects or the underlying psychiatric condition 3
• Normal EKG 30 days ago provides reassurance, though does not completely exclude cardiac disease 1, 2

Cardiac Risk Factors Present:

• Age 49 years (moderate risk) 2
• Male gender increases probability of cardiac disease 3

Lamotrigine Safety Considerations

Lamotrigine at 25 mg daily carries minimal cardiac risk but requires monitoring for rash, which can be life-threatening. 4, 5

• The FDA added a warning in 2020 regarding potential cardiac rhythm and conduction abnormalities with lamotrigine, but retrospective data in vulnerable populations showed only 7.3% had potential EKG abnormalities, with no deaths from cardiac causes 4
• Approximately 7-10% of patients develop skin rash with lamotrigine, which can progress to Stevens-Johnson syndrome 6, 7
• The patient's reported "spider bite" must be carefully examined to distinguish true cellulitis from early lamotrigine-related rash, which would require immediate drug discontinuation 6, 5
• Rare cases of lamotrigine-induced myocarditis have been reported, presenting with chest pain and elevated cardiac enzymes 5

Recommended Management Algorithm

Step 1: Evaluate the Skin Lesion (Priority)

• If the lesion shows characteristics of cellulitis (warmth, erythema, induration, tenderness), initiate appropriate antibiotic therapy 1
• If the lesion appears vesicular, has surrounding erythema in a non-infectious pattern, or is accompanied by other skin changes, consider lamotrigine hypersensitivity and contact the prescribing mental health provider immediately 6, 5

Step 2: Chest Pain Assessment (Secondary Priority)

• Since the patient reports no chest pain during this visit and no episodes since medication change, active cardiac workup is not indicated 1, 2
• Document that chest pain has completely resolved 2
• Reinforce education about cardiac warning signs: chest pain at rest lasting >5 minutes, pain with exertion, associated dyspnea, diaphoresis, nausea, or radiation to jaw/arm should prompt immediate emergency evaluation 1, 2

Step 3: Medication Monitoring

• Continue lamotrigine 25 mg as prescribed by mental health team 4
• Monitor for rash development at each visit, as this is the most common serious adverse effect 6, 7
• No routine EKG is required for lamotrigine monitoring at this low dose in the absence of cardiac symptoms 4

Critical Pitfalls to Avoid

• Do not dismiss the skin lesion as a simple "spider bite" without thorough examination, as both cellulitis and drug hypersensitivity can present with localized warmth and induration 1, 6
• Do not assume resolved chest pain means no future cardiac risk; the patient requires education about when to seek emergency care 1, 2
• Do not attribute all symptoms to psychiatric medication changes without excluding organic pathology 3
• Do not delay antibiotic treatment if cellulitis is present, as skin infections can progress rapidly in correctional settings 1

Follow-Up Plan

• Reassess the skin lesion in 24-48 hours if cellulitis treatment is initiated, or immediately if drug reaction is suspected 1, 6
• Schedule routine follow-up in 2-4 weeks to monitor lamotrigine tolerance and ensure chest pain remains resolved 4
• Coordinate with mental health team regarding any concerns about lamotrigine-related adverse effects 4, 5