What is the treatment for a 14-year-old female with a 4-day history of pruritic (itchy) rash with erythematous (red) papules (raised bumps) on the face and extremities, following mango consumption, without fever or flu-like symptoms?

Treatment of Suspected Mango-Induced Allergic Contact Dermatitis

This 14-year-old female most likely has allergic contact dermatitis to mango, and should be treated with topical hydrocortisone 1% cream applied to affected areas 3-4 times daily, combined with oral antihistamines for pruritus control. 1, 2

Immediate Management Approach

First-Line Topical Therapy

• Apply hydrocortisone 1% cream to all affected areas (face and extremities) 3-4 times daily, as this is the FDA-approved treatment for itching, inflammation, and rashes in patients 2 years and older 2
• Hydrocortisone 1% is specifically recommended for facial and extremity involvement, avoiding the risk of skin atrophy associated with more potent corticosteroids 1
• Continue topical corticosteroid treatment until the rash resolves, typically within 1-2 weeks 1

Oral Antihistamine for Pruritus

• Prescribe a non-sedating antihistamine for daytime use: loratadine 10 mg daily OR cetirizine 10 mg daily OR fexofenadine 180 mg daily 1, 3
• These second-generation antihistamines are preferred over diphenhydramine during daytime to avoid sedation while providing effective antipruritic relief 3, 4
• For nighttime pruritus interfering with sleep, consider adding diphenhydramine 25-50 mg at bedtime due to its sedative properties 3

Essential Supportive Care

• Instruct the patient to apply emollients liberally and frequently to all affected areas, as this forms the foundation of treatment for any pruritic rash 1, 5
• Recommend high lipid-content moisturizers to maintain skin barrier function 4, 5
• Advise avoiding hot showers and excessive soap use, which can worsen xerosis 3

Clinical Reasoning: Mango Contact Dermatitis

Why This Diagnosis Fits

The temporal relationship between mango consumption and rash onset strongly suggests mango-induced allergic contact dermatitis 6, 7. Key diagnostic features include:

• Pruritic erythematous papules on face and extremities appearing the same day as mango exposure matches the classic presentation of mango contact dermatitis 7, 8
• The 4-day persistence is consistent with allergic contact dermatitis, which typically appears 24-72 hours after exposure and can persist for days to weeks 1
• Mango contains alk(en)yl catechols and alk(en)yl resorcinols (similar to poison ivy urushiol), which cause contact sensitization 6
• Contact dermatitis from mango can occur on first exposure if the patient was previously sensitized to related plants 6

Important Clinical Pitfall

Do NOT assume this is a systemic IgE-mediated food allergy simply because mango was ingested. The absence of fever, flu-like symptoms, respiratory symptoms, or gastrointestinal symptoms argues against anaphylaxis 9, 10. The distribution pattern (face and extremities where mango juice likely contacted skin during eating) and delayed onset support contact dermatitis rather than immediate hypersensitivity 6, 7.

Strict Avoidance Counseling

• Advise complete avoidance of mango fruit, including skin, flesh, and sap 6, 7
• Warn that cross-reactions may occur with cashew, poison ivy, poison oak, and other Anacardiaceae family plants 6
• Instruct the patient to wash hands thoroughly after any potential mango contact 7

Reassessment Strategy

If the rash worsens or fails to improve after 2 weeks of treatment, proceed with dermatology referral for patch testing 1, 5. Patch testing with mango skin and flesh extracts can confirm the diagnosis, though reagents are not standardized 6, 7.

Red Flags Requiring Urgent Evaluation

• Development of facial swelling, difficulty breathing, or systemic symptoms would indicate progression to anaphylaxis and requires emergency treatment with epinephrine 3, 9
• Painful lesions lasting >48 hours with systemic symptoms should prompt consideration of urticarial vasculitis and skin biopsy 1

Alternative Diagnoses to Consider if Treatment Fails

If symptoms persist beyond 2 weeks despite appropriate treatment, reconsider:

• Atopic dermatitis (would typically have chronic history, characteristic distribution, xerosis, and lichenification) 1
• Drug-induced rash (review all medications, as 12.5% of cutaneous drug reactions present as pruritus with rash) 5
• Early viral exanthem (though absence of fever makes this less likely) 5