What is the recommended dose of prednisone (corticosteroid) for an adult patient with an allergic reaction, considering factors such as severity, medical history, age, and weight?

Prednisone Dosing for Allergic Reactions in Adults

For acute allergic reactions requiring systemic corticosteroids, administer prednisone 1 mg/kg (maximum 60-80 mg) daily for 2-3 days, without tapering for short courses. 1

Severity-Based Treatment Algorithm

Anaphylaxis or Severe Allergic Reactions (Hospital Setting)

• First-line treatment is always epinephrine IM, not corticosteroids 1
• Prednisone 1 mg/kg (maximum 60-80 mg) orally OR methylprednisolone 1 mg/kg (maximum 60-80 mg) IV as adjunctive therapy 1
• Continue for 2-3 days after discharge to prevent biphasic reactions 1
• Corticosteroids are adjunctive only—they do not replace epinephrine and take 6-12 hours to exert anti-inflammatory effects 2

Acute Urticaria (Outpatient Setting)

• Prednisone 20 mg orally every 12 hours (40 mg/day total) for 4 days combined with antihistamines provides superior symptom relief compared to antihistamines alone 3
• Alternative regimen: Prednisone 25 mg/day for 3 days for antihistamine-resistant chronic urticaria 4
• This short burst significantly reduces pruritus and accelerates rash resolution without adverse effects 3
• Nearly 50% of patients with antihistamine-resistant urticaria achieve remission with a single short course 4

Moderate Allergic Reactions (Outpatient Setting)

• Prednisone 40-60 mg daily for 5-10 days is the standard outpatient burst regimen 5, 2
• Administer as a single morning dose to minimize HPA axis suppression 6
• No tapering required for courses ≤7-10 days 2

Critical Dosing Considerations

Weight-Based Calculations

• Standard adult dosing: 1 mg/kg/day with maximum 60-80 mg 1
• For a 70 kg adult: 70 mg, but practical maximum is 60-80 mg 1
• Higher doses (>80 mg) provide no additional benefit and increase adverse effects 2

Timing and Administration

• Administer in the morning (before 9 AM) to align with natural cortisol rhythm and minimize adrenal suppression 6
• Take with food or milk to reduce gastric irritation 6
• Oral administration is equally effective as IV when GI absorption is intact 2

Duration and Tapering Guidelines

Short Courses (≤7-10 days)

• No tapering necessary for courses lasting less than 7-10 days 2
• This applies to the standard 2-5 day burst for acute allergic reactions 1, 3

Longer Courses (>10 days)

• If treatment extends beyond 10 days, taper by reducing dose by 25-33% at appropriate intervals 5
• Gradual withdrawal prevents adrenal insufficiency 6

Concurrent Therapy

Essential Adjunctive Medications

• H1 antihistamine (diphenhydramine 1-2 mg/kg, maximum 50 mg) for immediate symptom relief 1
• H2 antihistamine (ranitidine 1-2 mg/kg, maximum 75-150 mg) may enhance response 1
• Continue antihistamines for 2-3 days after corticosteroid course 1

Critical Pitfalls to Avoid

Common Errors

• Never delay epinephrine in anaphylaxis to give corticosteroids first—epinephrine is the only life-saving intervention 1
• Do not use arbitrarily short courses (3 days) without assessing clinical response, as 5-10 days is evidence-based minimum for most allergic conditions 2
• Avoid unnecessarily high doses (>80 mg), which increase adverse effects without additional benefit 2
• Do not taper short courses (<7 days), as this is unnecessary and may lead to underdosing during the critical period 2

Special Populations

• Diabetic patients: Monitor glucose closely, as hyperglycemia is common 7
• Patients with GI bleeding history or on anticoagulants: Greatest risk for GI complications, though short courses carry very low absolute risk 2
• Asthmatic patients: May be at higher risk for allergic reactions to corticosteroids themselves 8

Alternative Corticosteroid Options

If prednisone is not tolerated or contraindicated:

• Prednisolone at equivalent doses (same mg-for-mg dosing) 1, 2
• Methylprednisolone 1 mg/kg (maximum 60-80 mg) IV or oral 1
• Dexamethasone may be used but has longer half-life and greater HPA suppression 2

Monitoring and Follow-Up

• Reassess clinical response at 2 days for urticaria 3
• Ensure resolution of symptoms before discontinuing therapy 1
• Educate patients on allergen avoidance and provide epinephrine auto-injector prescription for severe reactions 1
• Arrange follow-up with primary care physician within one week and consider allergy specialist referral 1