A 23-year-old man comes to the clinic for evaluation of a rash. He reports that reddish bumps began to develop on his shins 4 weeks ago. Although painful, they are not itchy. On review of systems, he notes that his stools have become looser than normal over the past 6 months and are associated with intermittent, crampy abdominal pain. He has unintentionally lost 5 kg (11 lb) in the past month. The patient has no hematochezia, nausea, vomiting, joint pains, night sweats, or fevers. Medical and family history are unremarkable. He does not use tobacco, alcohol, or illicit drugs. Temperature is 37.2 C (99 F), blood pressure is 113/72 mm Hg, pulse is 85/min, and respirations are 15/min. Physical examination reveals several 2- to 3-cm erythematous, tender, nonmobile nodules on the anterior aspect of both lower extremities. Careful skin examination reveals no other abnormalities. The abdomen is mildly tender to palpation but without distension, rebound, or guarding. Which of the following most likely explains this patient's presentation?

Question

A 23-year-old man comes to the clinic for evaluation of a rash.  He reports that reddish bumps began to develop on his shins 4 weeks ago.  Although painful, they are not itchy.  On review of systems, he notes that his stools have become looser than normal over the past 6 months and are associated with intermittent, crampy abdominal pain.  He has unintentionally lost 5 kg (11 lb) in the past month.  The patient has no hematochezia, nausea, vomiting, joint pains, night sweats, or fevers.  Medical and family history are unremarkable.  He does not use tobacco, alcohol, or illicit drugs.  Temperature is 37.2 C (99 F), blood pressure is 113/72 mm Hg, pulse is 85/min, and respirations are 15/min.  Physical examination reveals several 2- to 3-cm erythematous, tender, nonmobile nodules on the anterior aspect of both lower extremities.  Careful skin examination reveals no other abnormalities.  The abdomen is mildly tender to palpation but without distension, rebound, or guarding.  Which of the following most likely explains this patient's presentation?

Quizplus · Accepted Answer

This patient likely has erythema nodosum (EN) (eg, painful, erythematous nodules on his shins) in the setting of uncontrolled inflammatory bowel disease (IBD) (eg, chronic diarrhea, abdominal pain, weight loss). The association between EN and IBD is well recognized and more commonly occurs in Crohn disease than ulcerative colitis. EN mirrors IBD disease activity, meaning that it worsens during severe IBD flares and resolves as those flares improve. EN presents as tender, nonpruritic, erythematous, or violaceous nodules that typically measure 2-3 cm in size. The nodules are usually located on the shins but can develop elsewhere on the legs or on the upper extremities, buttocks, trunk, or face. EN results from a delayed-type hypersensitivity reaction to antigen exposure. Biopsy of the nodules reveals septal panniculitis without vasculitis. In addition to IBD, EN has other important disease associations, including sarcoidosis, malignancy (eg, Hodgkin lymphoma), and certain infections (eg, streptococcal, endemic fungal, viral mononucleosis). (Choice A) Campylobacter jejuni typically causes a self-limited gastroenteritis with diarrhea (bloody or non-bloody) that resolves within approximately 7 days. Although the organism has been reported to trigger EN, it more commonly causes reactive arthritis or Guillain-Barré syndrome. (Choice B) Celiac disease is associated with dermatitis herpetiformis, which presents with itchy papules and vesicles that are most prominent on the elbows and forearms. This patient's rash is inconsistent with dermatitis herpetiformis because it is nodular, nonitchy, and most prominent on the shins. (Choice C) Migratory superficial thrombophlebitis (eg, Trousseau syndrome) can be seen with adenocarcinoma of the colon, pancreas, or stomach. It usually presents with recurrent, tender nodules that appear on different parts of the body at different times. Because the nodules in this patient appeared simultaneously and only on the shins, Trousseau syndrome due to underlying malignancy is unlikely. (Choice D) IgA vasculitis, formerly called Henoch-Schoenlein purpura, presents most commonly in children with palpable purpura, joint pain, abdominal pain, and renal disease; chronic diarrhea is not a prominent symptom. Educational objective: Erythema nodosum presents with tender, nonpruritic, erythematous, or violaceous nodules measuring 2-3 cm and usually located on the shins. It has a strong association with inflammatory bowel disease (IBD), especially Crohn disease, and its presence correlates with the degree of IBD activity.

A 23-Year-Old Man Comes to the Clinic for Evaluation of a Rash