Yetsenia

Question 1

An 18-year-old woman presented with new-onset low-grade fever, sore throat, and arthralgia. She had just recovered from 2 weeks of diarrhea, which she ascribed to eating some undercooked pork. She did not take regular medications and had no recent travel outside of her country. On examination, her throat was unremarkable, her small and large joints were normal, but there were multiple tender nodules 3-4 cm in diameter palpable over both shins. Her serum TSH was noted to be elevated, although she showed no signs of Graves’ disease.

Answer 1

a) What is the most likely causative organism for her recent diarrhea?
*Yersenia
عرفتها ازاي ؟
post-infectious complications such as arthritis, erythema nodosum, and autoimmune thyroiditis.

Question 2

b) What is the cause of the elevated TSH in this case?

Answer 2

Post-infectious (autoimmune) thyroiditis induced by Yersinia enterocolitica

Question 3

c) What is the cause of arthralgia and shin nodules?

Answer 3

*Arthralgia is due to reactive arthritis.
*Tender nodules over the shins are characteristic of erythema nodosum, a panniculitis often associated with infections (notably Yersinia, Streptococcus, TB, and sarcoidosis).

Question 4

DD of erythema nodosum

Answer 4

Erythema nodosum is a type of panniculitis (inflammation of subcutaneous fat) that presents as tender, red nodules, usually on the shins.
Causes
TB
Sarcoid
Streptococcus (the most common cause)
Yersenia
IBD
Behçet’s disease
Histoplasmosis

Coccidioidomycosis

Chlamydia

Campylobacter

Mycoplasma

Epstein-Barr virus (EBV)