In a female patient who develops erythematous, pruritic palms after taking a two‑part regimen of mifepristone and misoprostol for abortion, what conditions should be ruled out?

Differential Diagnosis for Red Itchy Palms After Medical Abortion

This patient most likely has a drug hypersensitivity reaction to misoprostol, but you must immediately rule out serious mucocutaneous reactions (Stevens-Johnson syndrome/toxic epidermal necrolysis), angioedema with potential airway compromise, and erythema multiforme before attributing symptoms to a benign drug reaction.

Immediate Life-Threatening Conditions to Exclude

1. Angioedema

• Angioedema is documented in the FDA postmarketing surveillance for mifepristone 1
• Assess for:
  • Facial swelling, lip swelling, tongue swelling
  • Difficulty breathing or stridor
  • Throat tightness
  • This requires immediate intervention to prevent airway obstruction 2
• One case report documented hypersensitivity to sublingual misoprostol requiring prompt intervention to prevent life-threatening airway obstruction 2

2. Stevens-Johnson Syndrome (SJS) / Toxic Epidermal Necrolysis (TEN)

• Toxic epidermal necrolysis has been reported with misoprostol 3
• Look for:
  • Mucosal involvement (oral, ocular, genital lesions)
  • Skin detachment or blistering beyond the palms
  • Fever
  • Systemic symptoms
• If any bullous or exfoliative rash is present, immediately discontinue all medications 4
• A 25-year-old woman developed TEN after three doses of misoprostol 200 mcg, requiring four weeks of treatment 3

3. Erythema Multiforme (EM)

• Erythema multiforme has been documented with misoprostol 5
• Examine for:
  • Target lesions (classic "bulls-eye" appearance)
  • Oral mucosal lesions (white bullae, hyperkeratotic plaques)
  • Distribution on palms, soles, and extensor surfaces
• One case showed oral bullae lesions and hyperkeratotic lip plaques that resolved in 3 weeks 5
• Important caveat: EM can progress to SJS in subsequent exposures, so documentation and patient counseling are critical 5

Other Drug Reactions to Consider

4. Simple Drug Hypersensitivity/Allergic Reaction

• Generalized maculopapular rash was reported in 4% of patients taking mifepristone, and pruritus in another 4% 1
• Misoprostol hypersensitivity reactions are rare but documented 2
• Assess for:
  • Distribution: Is it limited to palms or more widespread?
  • Urticaria or hives
  • Timing: Onset within hours to days of medication
  • Associated symptoms: pruritus without systemic involvement

5. Hand-Foot Skin Reaction (Palmar-Plantar Erythrodysesthesia)

• While this is classically associated with EGFR inhibitors and certain chemotherapy agents 4, the presentation of erythematous, pruritic palms warrants consideration
• However, this is unlikely in the abortion medication context as it's not documented with mifepristone/misoprostol

Non-Drug Related Conditions

6. Infection

• Rule out:
  • Scabies (interdigital webbing involvement, burrows)
  • Secondary syphilis (palmar rash with systemic symptoms)
  • Viral exanthems
• Consider if there's epidemiological exposure or other systemic signs

7. Contact Dermatitis

• New exposures to soaps, lotions, or other contactants
• Typically bilateral and symmetric on palms
• Less likely to be intensely pruritic without vesiculation

Clinical Approach Algorithm

1. First 5 minutes: Assess airway, breathing, circulation

   • Any facial/tongue swelling, stridor, or respiratory distress? → Treat as angioedema emergency

2. Skin examination:

   • Bullae, skin detachment, or >10% body surface area involvement? → Consider SJS/TEN, hospitalize immediately
   • Target lesions with mucosal involvement? → Likely erythema multiforme, close monitoring
   • Isolated palmar erythema with pruritus, no mucosal involvement? → Likely simple drug reaction

3. Mucosal examination:

   • Check oral mucosa, conjunctiva, and genital mucosa for lesions
   • Presence of mucosal lesions elevates concern significantly

4. Timing and progression:

   • Rapid onset (hours) suggests IgE-mediated hypersensitivity
   • Delayed onset (days) suggests T-cell mediated reaction

Management Recommendations

• If SJS/TEN suspected: Immediate hospitalization, discontinue all medications, supportive care, consider dermatology/burn unit consultation
• If angioedema: Epinephrine, antihistamines, corticosteroids, airway management
• If erythema multiforme: Discontinue medications, supportive care, close follow-up (risk of progression)
• If simple drug reaction: Antihistamines (H1-blockers), topical corticosteroids, discontinue offending agent if severe 4

Critical Counseling Point

Patients choosing home-based medical abortion must be counseled about these rare but serious hypersensitivity reactions and instructed to seek immediate medical attention for any rash, especially if accompanied by mucosal lesions, facial swelling, or difficulty breathing 2.