WBR0769
| Author | [[PageAuthor::Serge Korjian M.D.(Reviewed by Serge Korjian)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Dermatology |
| Prompt | [[Prompt::A 14 year-old-boy is brought to the physician's office by his mother for multiple pruritic lesions on his legs. The mother informs the physician that the child had recently returned from a picnic and she fears he has been exposed to poison ivy. On physical examination, the physician notes vesicular bullous lesions with erythema on the lower extremities. The patient's condition is best characterized by a hypersensitivity disorder that resembles which other disease?]] |
| Answer A | AnswerA::Pernicious anemia |
| Answer A Explanation | AnswerAExp::Pernicious anemia is a type II hypersensitivity disorder. |
| Answer B | AnswerB::Multiple sclerosis (MS) |
| Answer B Explanation | AnswerBExp::MS is caused by a type IV hypersensitivity disorder. |
| Answer C | AnswerC::Systemic lupus erythematosus (SLE) |
| Answer C Explanation | AnswerCExp::SLE is caused by a type III hypersensitivity disorder. |
| Answer D | AnswerD::Atopic dermatitis |
| Answer D Explanation | AnswerDExp::Eczema or atopic dermatitis is caused by a type I hypersensitivity disorder. |
| Answer E | AnswerE::Poststreptococcal glomerulonephritis (PSGN) |
| Answer E Explanation | AnswerEExp::PSGN is a caused by a type III hypersensitivity disorder. |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::The patient is presenting with contact dermatitis following exposure to poison ivy, a common allergen. Contact dermatitis is caused by a type IV (delayed) hypersensitivity reaction. Similarly, multiple sclerosis is also caused by a type IV hypersensitivity disorder. Other diseases that are also implicated in this type of disorder are: Guillain-Barre syndrome, graft-vs-host disease, and PPD testing for Mycobacterium tuberculosis. Educational Objective: Contact dermatitis and multiple sclerosis are both caused by a type IV hypersensitivity disorder. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Multiple sclerosis, WBRKeyword::Type III hypersensitivity, WBRKeyword::Hypersensitivity disorder, WBRKeyword::Hypersensitivity, WBRKeyword::Dermatitis, WBRKeyword::Irritant, WBRKeyword::Allergic, WBRKeyword::Allergy, WBRKeyword::Atopic, WBRKeyword::Atopy |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |