WBR1001

Author	[[PageAuthor::Vidit Bhargava, M.B.B.S [1]]]
Exam Type	ExamType::USMLE Step 2 CK
Main Category	MainCategory::Internal medicine
Sub Category	SubCategory::Dermatology
Prompt	[[Prompt::A 30 yr old male presents to the clinic with an erythematous, pruritic rash as shown below. The rash spares palms and soles, but involves the back and chest. What Is the most likely diagnosis? ]]
Answer A	[[AnswerA::Secondary syphilis]]
Answer A Explanation	AnswerAExp::Secondary syphilis presents with a symmetrical, reddish-pink, non-itchy rash on the trunk and extremities, including the palms and soles.
Answer B	[[AnswerB::Pityriasis rosea]]
Answer B Explanation	[[AnswerBExp::It is a fine maculo-papular rash, that begins as 2-10 cm oval red 'herald patch' classically on the abdomen. 7–14 days after the herald patch, many small (5-10 mm) patches of pink or red, flaky, oval-shaped rash appear on the chest or back. The small oval patches may spread in a characteristic pattern called as 'Christmas tree' appearance. The rash may be mild to intensely itchy. It is a self limited condition which usually resolves in 6-8 weeks.]]
Answer C	[[AnswerC::Pityriasis versicolor]]
Answer C Explanation	[[AnswerCExp::It is a fungal infection caused by fungus Malassezia. It can present with one of the following: Generally oval or irregularly-shaped spots of 1/4 to 1 inch in diameter, often merging together to form a larger patch. Occasional fine scaling of the skin producing a very superficial ash-like scale. Pale, dark tan, or pink in color, with a reddish undertone that can darken when the patient is overheated, such as in a hot shower or during/after exercise. Sharp border ]]
Answer D	[[AnswerD::Herpes Zoster]]
Answer D Explanation	[[AnswerDExp::Herpes zoster commonly known as shingles, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute (short-lived) illness chickenpox, and generally occurs in children and young people. Once an episode of chickenpox has resolved, the virus is not eliminated from the body but can go on to cause shingles—an illness with very different symptoms—often many years after the initial infection. ]]
Answer E	[[AnswerE::Psoriasis]]
Answer E Explanation	[[AnswerEExp::Psoriasis is a disease which affects the skin and joints. It commonly causes red scaly patches to appear on the skin. The scaly patches caused by psoriasis, called psoriatic plaques, are areas of inflammation and excessive skin production. Skin rapidly accumulates at these sites and takes a silvery-white appearance. Plaques frequently occur on the skin of the elbows and knees, but can affect any area including the scalp and genitals. Psoriasis is hypothesized to be immune-mediated and is not contagious. ]]
Right Answer	RightAnswer::B
Explanation	[[Explanation::Christmas tree appearance, herald patch, and a whole body rash that spares palms and soles is characteristic of pityriasis rosea. It can be easily confused with other similar conditions such as syphilis, pityriasis versicolor, herpes zoster etc but a close examination and careful history taking are oftem sufficient to make the diagnosis. Educational Objective: Involvement of palms and soles favors the diagnosis of pityriasis rosea, along with herald patch and Christmas tree appearance. References: Page 101 FA STEP2CK seventh edition]]
Approved	Approved::Yes
Keyword	WBRKeyword::Skin, WBRKeyword::Dermatology
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::