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{{WBRQuestion
{{WBRQuestion
|QuestionAuthor={{Rim}}
|QuestionAuthor= {{YD}} (Reviewed by  {{YD}} and  {{AJL}})
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Physiology
|MainCategory=Pathophysiology
|SubCategory=Musculoskeletal/Rheumatology
|SubCategory=Dermatology
|MainCategory=Physiology
|MainCategory=Pathophysiology
|SubCategory=Musculoskeletal/Rheumatology
|SubCategory=Dermatology
|MainCategory=Physiology
|MainCategory=Pathophysiology
|SubCategory=Musculoskeletal/Rheumatology
|SubCategory=Dermatology
|MainCategory=Physiology
|MainCategory=Pathophysiology
|MainCategory=Physiology
|MainCategory=Pathophysiology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Pathophysiology
|MainCategory=Physiology
|SubCategory=Dermatology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Pathophysiology
|MainCategory=Physiology
|SubCategory=Dermatology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Pathophysiology
|MainCategory=Physiology
|SubCategory=Dermatology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Pathophysiology
|MainCategory=Physiology
|SubCategory=Dermatology
|MainCategory=Physiology
|MainCategory=Pathophysiology
|SubCategory=Musculoskeletal/Rheumatology
|MainCategory=Pathophysiology
|Prompt=A 40 year old female patient presents to her dermatologist complaining of several skin lesions. On physical examination, the physician notes several intraepidermal bullae with flaccid blisters and an epidermal layer that easily comes off with manual stroking. Which of the following processes characterize the disease in this patient?
|SubCategory=Dermatology
|Explanation=Pemphigus vulgaris is an autoimmune dermatologic disease due to IgG antibodies against desmosomes that causes acantholysis, defined as loss of cohesion between the keratinocytes in the epidermal layer. Pemphigus vulgaris is characterized by formation of intraepidermal bullae that cause flaccid blisters with positive Nicolsky's sign, defined as easy separation of epidermal layer upon manual stroking.  
|Prompt=A 50-year-old woman presents to her dermatologist with complaints of multiple skin lesions. Physical examination is remarkable for flaccid skin blisters. The upper epidermal layer is easily removed with manual stroking or gentle pressure. Immunofluorescence demonstrates antibodies surrounding the cells in a net-like pattern. Which of the following processes best characterizes the patient's disease?
 
|Explanation=[[Pemphigus vulgaris]] (PV) is a rare, chronic, autoimmune blistering disease of the skin and mucous membranes. The majority of patients who are diagnosed with PV are between the age of 40 and 60 years. It is caused by IgG auto-antibodies against desmoglein of desomosomes (epidermal keratinocyte desmosomal cadherins) and results in flaccid intraepidermal bullae formation and acantholysis, defined as the loss of adhesion between the keratinocytes in the epidermal layer. On physical examination, a positive Nicolsky sign is typically present. Nicolsky sign is the loss of the upper epidermal layer is easily removed with manual stroking or gentle pressure. The diagnosis of PV is made by immunofluorescence that demonstrates antibodies surrounding epidermal cells in a net-like or reticular pattern. Treatment includes systemic corticosteroids and steroid-sparing agents.
Educational Objective:
|AnswerA=IgG antibodies against cadherins
Pemphigus vulgaris is an autoimmune dermatological disease characterized by IgG antibody against desmosome.
|AnswerAExp=[[Pemphigus vulgaris]] results from IgG antibodies against demoglein, a member of the cadherin family and a component of desmosomes.
|AnswerA=IgG antibodies against desmosome
|AnswerB=IgM antibodies against desmosomes
|AnswerAExp=Pemphigus vulgaris is characterized by IgG antibodies against desmosome.
|AnswerBExp=[[Pemphigus vulgaris]] results from IgG antibodies against desmosomes, not IgM desmosomes.
|AnswerB=IgM antibodies against desmosome
|AnswerC=IgG antibodies against hemidesmosomes
|AnswerBExp=Pemphigus vulgaris is characterized by IgG antibodies against desmosome, not IgM desmosome.
|AnswerCExp=Bullous pemphigoid is an autoimmune disorder that results from IgG auto-antibodies against hemidesmosomes. Unlike pemphigus vulgaris, bullous pemphigoid is not life-threatening. To distinguish both conditions, bullous pemphigoid is characterized by IgG antibodies in the epidermal basement membrane, while PV is characterized by intraepidermal IgG antibodies. Also, immunofluorescence in bullous pemphigoid demonstrates a linear pattern at the epidermal-dermal junction, while it demonstrates a net-like or reticular pattern in pemphigus vulgaris.
|AnswerC=IgG antibodies against hemidesmosome
|AnswerD=IgM antibodies against hemidesmosomes
|AnswerCExp=Bullous pemphigoid is characterized by IgG antibodies against hemidesmosome
|AnswerDExp=[[Pemphigus vulgaris]] does not result from auto-antibodies against hemidesmosomes. Also, bullous pemphigoid is caused by IgG antibodies against hemidesmosomes, not IgM antibodies.
|AnswerD=IgM antibodies against hemidesmosome
|AnswerE=IgE antibodies against hemidesmosomes
|AnswerDExp=Pemphigus vulgaris is not due to auto-antibodies against hemidesmosome
|AnswerEExp=Pemphigus vulgaris does not result from auto-antibodies against hemidesmosomes. Also, bullous pemphigoid is caused by IgG antibodies against hemidesmosomes, not IgE antibodies.
|AnswerE=IgE antibodies against hemidesmosome
|EducationalObjectives=[[Pemphigus vulgaris]] (PV) is a rare, chronic, autoimmune blistering disease of the skin and mucous membranes. It is caused by IgG auto-antibodies against desmoglein of desomosomes (epidermal keratinocyte desmosomal cadherins) and results in flaccid intraepidermal bullae formation, acantholysis, and a positive Nicolsky sign on physical examination.
|AnswerEExp=Pemphigus vulgaris is not due to auto-antibodies against hemidesmosome
|References=Chmurova N, Svecova D. Pemphigus vulgaris: a 11-year review. Bartisl Lek Listy. 2009;110(8):500-3.<br>
First Aid 2014 page 434
|RightAnswer=A
|RightAnswer=A
|WBRKeyword=pemphigus, vulgaris, pemphigus vulgaris, IgG, auto, antibodies, antibody, autoantibody, autoantibodies, desmosome, blisters, blisters, bullae, acantholysis, nicolsky's, nicolsky
|WBRKeyword=Pemphigus vulgaris, Pemphigus, Bullous, Bullae, Desmosome, Desmoglein, Cadherin, Keratinocyte, Flaccid blisters, Skin lesions, Nicolsky sign, IgG, Autoantibodies, Antibodies, Autoimmune, Intraepidermal, Acantholysis
|Approved=No
|Approved=Yes
}}
}}

Latest revision as of 00:42, 28 October 2020
Author [[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Yazan Daaboul, M.D. and Alison Leibowitz [1])]]
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathophysiology
Sub Category SubCategory::Dermatology
Prompt [[Prompt::A 50-year-old woman presents to her dermatologist with complaints of multiple skin lesions. Physical examination is remarkable for flaccid skin blisters. The upper epidermal layer is easily removed with manual stroking or gentle pressure. Immunofluorescence demonstrates antibodies surrounding the cells in a net-like pattern. Which of the following processes best characterizes the patient's disease?]]
Answer A AnswerA::IgG antibodies against cadherins
Answer A Explanation [[AnswerAExp::Pemphigus vulgaris results from IgG antibodies against demoglein, a member of the cadherin family and a component of desmosomes.]]
Answer B AnswerB::IgM antibodies against desmosomes
Answer B Explanation [[AnswerBExp::Pemphigus vulgaris results from IgG antibodies against desmosomes, not IgM desmosomes.]]
Answer C AnswerC::IgG antibodies against hemidesmosomes
Answer C Explanation [[AnswerCExp::Bullous pemphigoid is an autoimmune disorder that results from IgG auto-antibodies against hemidesmosomes. Unlike pemphigus vulgaris, bullous pemphigoid is not life-threatening. To distinguish both conditions, bullous pemphigoid is characterized by IgG antibodies in the epidermal basement membrane, while PV is characterized by intraepidermal IgG antibodies. Also, immunofluorescence in bullous pemphigoid demonstrates a linear pattern at the epidermal-dermal junction, while it demonstrates a net-like or reticular pattern in pemphigus vulgaris.]]
Answer D AnswerD::IgM antibodies against hemidesmosomes
Answer D Explanation [[AnswerDExp::Pemphigus vulgaris does not result from auto-antibodies against hemidesmosomes. Also, bullous pemphigoid is caused by IgG antibodies against hemidesmosomes, not IgM antibodies.]]
Answer E AnswerE::IgE antibodies against hemidesmosomes
Answer E Explanation AnswerEExp::Pemphigus vulgaris does not result from auto-antibodies against hemidesmosomes. Also, bullous pemphigoid is caused by IgG antibodies against hemidesmosomes, not IgE antibodies.
Right Answer RightAnswer::A
Explanation [[Explanation::Pemphigus vulgaris (PV) is a rare, chronic, autoimmune blistering disease of the skin and mucous membranes. The majority of patients who are diagnosed with PV are between the age of 40 and 60 years. It is caused by IgG auto-antibodies against desmoglein of desomosomes (epidermal keratinocyte desmosomal cadherins) and results in flaccid intraepidermal bullae formation and acantholysis, defined as the loss of adhesion between the keratinocytes in the epidermal layer. On physical examination, a positive Nicolsky sign is typically present. Nicolsky sign is the loss of the upper epidermal layer is easily removed with manual stroking or gentle pressure. The diagnosis of PV is made by immunofluorescence that demonstrates antibodies surrounding epidermal cells in a net-like or reticular pattern. Treatment includes systemic corticosteroids and steroid-sparing agents.

Educational Objective: Pemphigus vulgaris (PV) is a rare, chronic, autoimmune blistering disease of the skin and mucous membranes. It is caused by IgG auto-antibodies against desmoglein of desomosomes (epidermal keratinocyte desmosomal cadherins) and results in flaccid intraepidermal bullae formation, acantholysis, and a positive Nicolsky sign on physical examination.
References: Chmurova N, Svecova D. Pemphigus vulgaris: a 11-year review. Bartisl Lek Listy. 2009;110(8):500-3.
First Aid 2014 page 434]]

Approved Approved::Yes
Keyword WBRKeyword::Pemphigus vulgaris, WBRKeyword::Pemphigus, WBRKeyword::Bullous, WBRKeyword::Bullae, WBRKeyword::Desmosome, WBRKeyword::Desmoglein, WBRKeyword::Cadherin, WBRKeyword::Keratinocyte, WBRKeyword::Flaccid blisters, WBRKeyword::Skin lesions, WBRKeyword::Nicolsky sign, WBRKeyword::IgG, WBRKeyword::Autoantibodies, WBRKeyword::Antibodies, WBRKeyword::Autoimmune, WBRKeyword::Intraepidermal, WBRKeyword::Acantholysis
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