Model Answer
0 min readIntroduction
Contact dermatitis is a common inflammatory skin condition resulting from direct contact with an irritant or allergen. It manifests as an eczematous reaction characterized by erythema, edema, vesicles, and pruritus. The incidence of contact dermatitis is increasing globally, largely due to increased exposure to potential allergens and irritants in everyday life. The clinical presentation of an adolescent girl with itchy, papulo-vesicular lesions on areas in contact with artificial jewelry strongly suggests allergic contact dermatitis, a type IV hypersensitivity reaction. This answer will detail the diagnosis, investigations, and management of this condition.
Understanding Contact Dermatitis
Contact dermatitis is broadly classified into two types: irritant contact dermatitis (ICD) and allergic contact dermatitis (ACD). ICD results from direct damage to the skin barrier by an irritant, while ACD is a cell-mediated immune response to an allergen.
Allergic Contact Dermatitis: The Likely Diagnosis
Given the presentation – itchy, papulo-vesicular lesions specifically on the ears, wrists, and neck (common sites for jewelry contact) – allergic contact dermatitis is the most probable diagnosis. Artificial jewelry often contains nickel, a common allergen. The lesions represent a delayed-type hypersensitivity reaction. The process involves:
- Sensitization Phase: Initial exposure to the allergen (nickel) doesn't cause a reaction but primes the immune system.
- Elicitation Phase: Subsequent exposure triggers an immune response, leading to inflammation and the characteristic skin lesions.
Common Allergens in Jewelry
Several metals and other substances used in jewelry can cause ACD:
- Nickel: The most common allergen in jewelry.
- Cobalt: Often found in alloys with nickel.
- Chromium: Another common metal allergen.
- Acrylic resins: Used in some plastic jewelry.
- Fragrances & Preservatives: Present in some jewelry adhesives.
Differential Diagnosis
While ACD is most likely, other conditions should be considered:
- Irritant Contact Dermatitis: Less likely given the vesicular nature of the lesions, but possible if the jewelry is causing mechanical irritation.
- Atopic Dermatitis: Can present with similar lesions, but typically affects flexural areas and has a personal or family history of atopy.
- Scabies: Intense itching, but lesions are typically burrows and involve interdigital spaces.
- Bullous Pemphigoid: Rare in adolescents, presents with tense blisters.
Investigations
Diagnosis is primarily clinical, but investigations can confirm the diagnosis and identify the allergen:
- Patch Testing: The gold standard for diagnosing ACD. Small amounts of potential allergens are applied to the skin under occlusive patches for 48-72 hours. The skin is then assessed for a reaction. Standard series of allergens, including nickel sulfate, should be tested.
- Skin Biopsy: Rarely needed, but can help rule out other conditions.
Management
Management focuses on removing the allergen, reducing inflammation, and relieving symptoms:
- Avoidance: The most important step. The patient should discontinue wearing the offending jewelry.
- Topical Corticosteroids: Potent topical corticosteroids (e.g., betamethasone dipropionate) can reduce inflammation and itching. Use for a limited duration to avoid side effects.
- Emollients: Frequent use of emollients helps restore the skin barrier.
- Systemic Corticosteroids: Reserved for severe, widespread cases.
- Antihistamines: Can help relieve itching, especially at night.
- Barrier Creams: Applying a barrier cream (e.g., dimethicone) before wearing jewelry *may* offer some protection, but avoidance is preferred.
Long-Term Management
Patients should be educated about potential allergens and how to avoid them. They should also be advised to choose hypoallergenic jewelry made of materials like surgical stainless steel, titanium, or gold (14k or higher).
Conclusion
In conclusion, the adolescent girl’s presentation is highly suggestive of allergic contact dermatitis caused by nickel in artificial jewelry. Accurate diagnosis through clinical assessment and patch testing is crucial. Management involves strict avoidance of the allergen, topical corticosteroids for symptom relief, and patient education. Long-term prevention relies on choosing hypoallergenic jewelry and avoiding potential allergens. Early diagnosis and appropriate management can prevent chronic dermatitis and improve the patient’s quality of life.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.