What is the plan of care for a patient experiencing a topical pruritic dermatitis allergic reaction after a total knee replacement?

Management of Topical Prineo Dermatitis Allergic Reaction Post Total Knee Replacement

For a patient with a topical pruritic dermatitis allergic reaction after total knee replacement, the recommended treatment is moderate to high-potency topical corticosteroids applied to the affected area 3-4 times daily, combined with oral antihistamines for symptomatic relief.

Initial Assessment and Treatment

• Rule out infection as the first step before treating as allergic dermatitis 1
• Apply moderate to high-potency topical corticosteroids to the affected area 3-4 times daily 2, 3
• Consider oral antihistamines for symptomatic relief of pruritus:
  • Non-sedating antihistamines (loratadine 10 mg, fexofenadine 180 mg) for daytime use 2, 4
  • First-generation antihistamines (diphenhydramine 25-50 mg) may be considered for nighttime use due to sedative properties 2

Specific Management for Prineo-Related Dermatitis

• Prineo wound-closure system has been documented to cause allergic contact dermatitis in total knee arthroplasty patients 1
• The allergic reaction typically presents as erythematous, blistering, pruritic rash around the incision site 1
• Treatment with topical corticosteroids and oral antibiotics (cephalexin) has been shown to resolve the reaction within weeks 1

Treatment Algorithm Based on Severity

For Mild Localized Reactions (Grade 1)

• Continue monitoring the reaction 2
• Apply moderate to high-potency topical corticosteroids 2, 3
• Reassess after 2 weeks; if worsening or not improving, proceed to next step 2

For Moderate Widespread Reactions (Grade 2)

• Continue monitoring the reaction 2
• Apply moderate to high-potency topical corticosteroids 2
• Add oral antihistamines 2, 4
• Consider gamma-aminobutyric acid (GABA) agonists (pregabalin/gabapentin) if pruritus is severe 2
• Reassess after 2 weeks; if worsening or not improving, proceed to next step 2

For Severe or Intolerable Reactions (Grade 3)

• Apply moderate to high-potency topical corticosteroids 2
• Use oral antihistamines 2
• Consider GABA agonists for severe pruritus 2
• Reassess after 2 weeks; if reactions worsen or do not improve, consider dermatology consultation 2, 4

Supportive Measures

• Use emollients to wash and moisturize the skin 2, 4
• Avoid soaps and physical triggers to pruritus such as wool clothing 2
• Menthol 0.5% preparations may provide symptomatic relief 2, 4
• Avoid crotamiton cream, topical capsaicin, and calamine lotion as they are not recommended for pruritus treatment 2

Important Considerations

• Allergic skin reactions following total knee replacement are rare but can occur even with hypoallergenic implants 5, 6
• Metal hypersensitivity should be considered but is not always the cause of post-operative dermatitis 6
• Adhesives used in surgical settings (like those in the Prineo system) can contain methacrylates that may cause allergic contact dermatitis 7
• Topical antibiotics are common causes of allergic contact dermatitis in post-operative wound care and should be considered as potential allergens 8

Follow-up and Monitoring

• Reassess the reaction after 2 weeks of treatment 2
• If the reaction persists or worsens despite appropriate treatment, consider dermatology referral for patch testing to identify specific allergens 4
• Document the allergic reaction to prevent future exposure to the same materials 1, 7