Allergic Contact Dermatitis from Plant Sap

Allergic contact dermatitis is an inflammatory skin reaction triggered by contact with an allergen. Certain plant saps, including that of the mango tree, contain urushiol-like compounds which can induce this reaction.

Clinical Presentation

Symptoms typically manifest within 12-48 hours of exposure. They include localized erythema (redness), itching, swelling, blistering, and in severe cases, weeping lesions. The rash is usually linear, following the path of sap contact. The severity of the reaction varies depending on the concentration of the allergen and individual sensitivity.

Management and Treatment

Immediate Actions

• Thoroughly wash the affected area with soap and water to remove any residual sap.
• Apply a cool compress to reduce inflammation and itching.
• Avoid scratching to prevent secondary infection and worsening of symptoms.

Pharmacological Interventions

• Topical corticosteroids: These are commonly prescribed to reduce inflammation and itching. Hydrocortisone creams are readily available over-the-counter, while stronger prescription-strength corticosteroids may be necessary for severe cases.
• Antihistamines: Oral or topical antihistamines can help alleviate itching. Oral antihistamines may cause drowsiness.
• Calamine lotion: This soothing lotion can provide relief from itching.

Additional Considerations

• Secondary bacterial infection: If the rash becomes infected, antibiotics may be required.
• Severe reactions: In cases of widespread or severe reactions, systemic corticosteroids may be necessary. Medical attention should be sought.
• Prevention: Wearing protective clothing and gloves during activities that could lead to exposure to mango sap is crucial for prevention. Thorough handwashing after handling mangoes is also essential.

Differential Diagnosis

Other skin conditions can mimic the appearance of allergic contact dermatitis. A medical professional should be consulted for accurate diagnosis and to rule out other possibilities.

Prognosis

Most cases resolve within a few days to weeks with appropriate management. However, recurrence is possible with subsequent exposure to the allergen. Desensitization therapy is not generally recommended for this type of allergic reaction.