WBR0769

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathology
Sub Category	SubCategory::Dermatology
Prompt	[[Prompt::A 14 year old boy is brought by his mother to the physician's office for pruritic lesions on his skin. The mother informs the physician that the child just recently returned from a picnic and had 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. Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::multiple, WBRKeyword::sclerosis, WBRKeyword::type III, WBRKeyword::hypersensitivity, WBRKeyword::disorder, WBRKeyword::type I, WBRKeyword::type II, WBRKeyword::type IV, WBRKeyword::dermatitis, WBRKeyword::contact, WBRKeyword::irritant, WBRKeyword::allergic, WBRKeyword::atopic
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::