Occupational Dermatoses Practice Questions

Q: A 40-year-old construction worker develops pruritic, erythematous papules on sun-exposed areas after handling wet cement. The lesions worsen with sun exposure. Which mechanism best explains this presentation?

Photoallergic contact dermatitis from chromium. ***Photoallergic contact dermatitis from chromium*** - **Hexavalent chromium** is a common sensitizer in **cement** that can undergo **photoactivation** by UV light to form a complete antigen, triggering a **Type IV hypersensitivity reaction**. - This presentation is classic for a worker exposed to wet cement who develops pruritic lesions specifically on **sun-exposed** areas due to the synergistic effect of the chemical and UV radiation. *Berloque dermatitis* - This is a specific type of **phytophotodermatitis** caused by the presence of **Bergapten** (a psoralen) in perfumes or colognes followed by sun exposure. - It typically presents with **pendant-shaped** hyperpigmentation rather than pruritic papules associated with cement work. *Phototoxic reaction from furocoumarins* - This occurs after skin contact with plants containing **psoralens** (like celery or lime) followed by UV light exposure, leading to a **non-immunologic** skin injury. - It typically manifests as a **painful** sunburn-like reaction or blistering, rather than the pruritic, eczematous papules seen in allergic reactions to chromium. *Solar urticaria* - This is a rare **physical urticaria** where wheals develop within minutes of exposure to sunlight and resolve quickly once the light source is removed. - It does not require a chemical trigger like **wet cement** and is mediated by **IgE** rather than the delayed-type hypersensitivity involved in contact dermatitis.

Question 1

A hospital implements a policy to reduce occupational hand dermatitis in healthcare workers. They propose: (A) Switching from latex to nitrile gloves, (B) Installing alcohol-based hand rub dispensers, (C) Providing emollients, (D) Reducing glove use frequency. Synthesize the best evidence-based strategy.

Accepted Answer

Implement A, B, and C; avoiding D as it compromises infection control

Answer

Implement all four measures as glove occlusion worsens dermatitis

Answer

Implement only A and C to reduce costs

Answer

Focus only on B and C as glove material is not the primary issue

Question 2

Evaluate the following scenario: A 38-year-old worker in an electronics manufacturing unit develops hand dermatitis. Initial patch testing shows multiple positive reactions to metals (nickel, cobalt, chromium). Despite workplace modifications and protective equipment, the dermatitis persists. Re-evaluation reveals positive patch test to colophony. What is the best strategic approach?

Accepted Answer

Colophony in soldering flux is the relevant occupational allergen; the metal sensitivities may be cross-reactions or co-sensitization

Answer

The persistent dermatitis indicates evolution to chronic actinic dermatitis

Answer

All positive reactions are equally relevant and complete job change is mandatory

Answer

The multiple sensitivities indicate systemic contact dermatitis requiring systemic therapy

Question 3

A 45-year-old florist develops dermatitis on hands and forearms. Patch testing shows positive reactions to Compositae mix and sesquiterpene lactones. She also has scattered airborne pattern dermatitis on face and neck. Analyzing this pattern, what is the most likely diagnosis?

Accepted Answer

Combined contact and airborne contact dermatitis from Compositae family plants

Answer

Irritant contact dermatitis from fertilizers

Answer

Phototoxic dermatitis from plant handling

Answer

Atopic dermatitis exacerbated by occupation

Question 4

A 32-year-old dental technician presents with hyperkeratotic fissured dermatitis on fingertips despite using vinyl gloves. Patch testing to rubber accelerators is negative, but shows positive reaction to methacrylate. Analysis of the clinical presentation suggests which underlying mechanism?

Accepted Answer

The methacrylate monomer penetrates vinyl gloves causing sensitization

Answer

Cross-reaction between vinyl and methacrylate

Answer

Protein contact dermatitis from dental materials

Answer

Irritant dermatitis unrelated to methacrylate sensitivity

Question 5

A 40-year-old construction worker develops pruritic, erythematous papules on sun-exposed areas after handling wet cement. The lesions worsen with sun exposure. Which mechanism best explains this presentation?

Accepted Answer

Photoallergic contact dermatitis from chromium

Answer

Berloque dermatitis

Answer

Phototoxic reaction from furocoumarins

Answer

Solar urticaria

Occupational Dermatoses — MCQs

Occupational Dermatoses — MCQs

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