WBR1088

Author	PageAuthor::Chetan Lokhande
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Community Medical Health Center
Sub Category	SubCategory::Infectious Disease, SubCategory::Allergy/Immunology, SubCategory::Infectious Disease, SubCategory::Respiratory
Prompt	[[Prompt::A 24 year old young engineer from Bangladesh complains of fever, cough and pain in the chest. On enquiry he says that he had these symptoms since 20 days. On examination the patient has a temperature of 38.3 C. Rest of the examination is unremarkable. A CT scan of the chest reveals the following image.Which of the following is the most likely diagnosis? File:thumb 300px]]
Answer A	AnswerA::Pulmonary aspergillosis
Answer A Explanation	[[AnswerAExp::Pulmonary aspergillosis is not common in Bangladesh. Also it is more common in immunocompromised patients and patients already having a cavity. Since no cavity could be seen on the CT this is not Pulmonary aspergillosis.]]
Answer B	AnswerB::Coccidioidomycosis
Answer B Explanation	[[AnswerBExp::Coccidioidomycosis commonly known as cocci, "valley fever", as well as "California fever", "desert rheumatism", and "San Joaquin Valley fever" is a mammalian fungal disease caused by Coccidioides immitis or Coccidioides posadasii. It is endemic in certain parts of Arizona, California, Nevada, New Mexico, Texas, Utah and northern Mexico. It is not endemic in Bangladesh.]]
Answer C	AnswerC::Miliary tuberculosis
Answer C Explanation	AnswerCExp::Tuberculosis is endemic in Bangladesh and presents with the symptoms described above in the question. CT scan shows classical small dots resembling "millets" which is very characteristic for Tuberculosis.
Answer D	AnswerD::Blastomycosis
Answer D Explanation	[[AnswerDExp::Blastomycosis is a fungal infection endemic to North America. Classical symptoms are flu-like illness with fever, chills, arthralgia (joint pain), myalgia (muscle pain), headache, and a nonproductive cough which resolves within days. It can also present as an acute illness resembling bacterial pneumonia, with symptoms of high fever, chills, a productive cough, and pleuritic chest pain.]]
Answer E	AnswerE::Histoplasma capsulatum
Answer E Explanation	[[AnswerEExp::Histoplasma capsulatum is a dimorphic fungi endemic to North America presents with symptoms similar to blastomycosis. Histoplasmosis is common among AIDS patients because of their suppressed immunity .The acute phase of histoplasmosis is characterized by non-specific respiratory symptoms, often cough or flu-like.]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::This patient is a young immigrant from Bangladesh presenting with classical symptoms of tuberculosis. CT scan shows classical small dots resembling "millets" which is very characteristic for Tuberculosis. Patient with miliary tuberculosis range from experiencing non-specific signs (ex: presence of coughing and enlarged lymph nodes). Miliary tuberculosis can also present with enlarged liver (40% of cases), enlarged spleen (15%), inflammation of the pancreas (<5%), and multiple organ dysfunction with adrenal insufficiency (adrenal glands do not produce enough steroid hormones to regulate organ function). Miliary tuberculosis may also present with unilateral or bilateral pneumothorax rarely. Stool may also be diarrheal in nature and appearance. Other symptoms include: fever, hypercalcemia, chorodial tubercles and cutaneous lesions. Firstly, many patients can experience a fever lasting several weeks with daily spikes in morning temperatures. Secondly, hypercalcemia prevails in 16 to 51% of tuberculosis cases. It is thought that hypocalemia occurs as a response to increased macrophage activity in the body. Such that, 1,25 dihydroxycholecalciferol (also referred to as calitriol) improves the ability of macrophages to kill bacteria; however, higher levels of calcitriol lead to higher calcium levels, and thus hypercalcemia in some cases. Thus, hypercalcemia proves to be an important symptom of miliary tuberculosis. Thirdly, Chorodial tubercules, pale lesions on the optic nerve, typically indicate miliary tuberculosis in children. These lesions may occur in one eye or both; the number of lesions varies between patients. Chorodial tubercules may serve as important symptoms of miliary tuberculosis, since their presence can often confirm suspected diagnosis. Lastly, between 10 to 30% of adults, and 20-40% of children with miliary tuberculosis have tuberculosis meningitis.[9] This relationship results from myobacteria from miliary tuberculosis spreading to the brain and the subarachnoid space; as a result, leading to tuberculosis meningitis. The risk factors for contracting miliary tuberculosis are being in direct contact with a person who has it, living in unsanitary conditions, and having an unhealthy diet. People in the U.S. that are at a higher risk for contracting the disease include the homeless and persons living with HIV/AIDS. Educational Objective: In a country with a high rate of population, tuberculosis is endemic and may present as miliary tuberculosis. Miliary tuberculosis may present as small white dots resembling like millets on the CT scan. References: ]]
Approved	Approved::Yes
Keyword	WBRKeyword::Miliary tuberculosis
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