Bilateral Adenopathy, Aching Ankles, and a Rash That Points Two Ways
Painful shin nodules, bilateral hilar adenopathy, and ankle arthralgia together describe a recognizable, usually self-limited syndrome — but the same imaging picture can also mean tuberculosis, and the two calls for very different next steps.
Camille O., a 26-year-old veterinary technician, presented with tender, red nodules across both shins that appeared over four days, accompanied by fevers to 38.2°C and pain in both ankles significant enough to limit her usual dog-walking route through the park near her apartment. A chest x-ray obtained in the emergency department, ordered mostly to rule out an obvious pulmonary cause for her fever, incidentally showed bilateral hilar lymphadenopathy — a finding that reframes what looked like an isolated skin complaint into something with a specific, recognizable shape.
The combination of erythema nodosum, bilateral hilar adenopathy, and ankle periarthritis together describes Löfgren syndrome, the acute sarcoidosis presentation Sven Löfgren set out in 1953 from a series of more than a hundred febrile young adults. The full triad runs at roughly 95% specificity for sarcoidosis, which is why it is one of the few presentations diagnosed without tissue at all, and something on the order of 85% of patients resolve spontaneously within two years. Camille does not merely fall inside that literature, she falls inside its sharpest slice: under forty, with bilateral ankle involvement of four days rather than months, a combination reported at about 95% specific in its own right. Camille has no other significant past medical history — no asthma, no prior autoimmune workup, no regular medications beyond an oral contraceptive she has taken without issue for six years, itself a recognized if less common trigger for erythema nodosum worth having noted and set aside given how well the rest of her picture fits the sarcoid triad instead.
That clinical confidence has a real limit worth stating plainly. Bilateral hilar adenopathy is not specific to sarcoidosis on imaging alone, and tuberculosis can produce a similar radiographic and even similar systemic picture, particularly in a patient with occupational animal exposure whose risk factors haven't yet been specifically asked about. Camille has no known TB contacts, no travel outside the country, and no prior positive TB test on record — reassuring, though incomplete, since no formal risk assessment or testing had actually been done before today's consult. The test itself is cheap in more than cost: an interferon-gamma release assay is expected to be negative in sarcoidosis, so a negative result costs nothing and a positive one would redirect the entire plan. She works closely with dogs and cats rather than livestock, which lowers though does not entirely remove the relevance of her occupation to any specific infectious differential, and she was, by her own account, feeling entirely well until four days ago — an acute, sudden-onset picture that itself fits Löfgren syndrome's typical presentation more than the more insidious course tuberculosis-associated adenopathy usually follows.
Pulmonology and rheumatology joint consult
This is a textbook Löfgren syndrome presentation — erythema nodosum, bilateral hilar adenopathy, ankle periarthritis, all together, all acute. It's specific enough — about 95% with the full triad — that, unlike most sarcoidosis presentations, it typically doesn't need a biopsy to confirm, and the prognosis is excellent: going back to Löfgren's own series, roughly 85% resolve spontaneously within two years. I'd manage her symptomatically with NSAIDs and follow the adenopathy on repeat imaging in a few months.
I don't want to talk her out of that read — the triad really is classic — but bilateral hilar adenopathy on its own isn't specific to sarcoidosis, and tuberculosis can produce a genuinely similar picture. She works with animals, which isn't itself a TB risk factor, but nobody has actually asked her about TB contacts or tested her before today.
I'm not proposing we treat this as TB until proven otherwise — I'm proposing we not skip the one cheap step that would tell us.
I think you're both actually pointing at the same plan without quite saying so. The clinical picture genuinely favors Löfgren syndrome — I agree that's the more likely read — but a targeted TB risk history plus an IGRA test is fast, cheap, and answers the one real gap in an otherwise reassuring picture, without requiring a biopsy or delaying symptomatic treatment for her ankles and skin either way.
So: NSAIDs started today for symptom control regardless of which diagnosis is correct, TB exposure history taken properly and IGRA sent, and a genuine sarcoidosis diagnosis of Löfgren syndrome confirmed once that comes back negative — rather than assumed outright from the imaging and rash alone.
Agreed: NSAIDs started today, TB exposure history taken in full, and IGRA testing sent — a plan that let the pulmonologist's clinical read and the infectious disease physician's caution both stand without either being set aside.
Her IGRA returned negative one week later, and her adenopathy and skin findings had already begun improving on NSAIDs alone by that follow-up visit — consistent with Löfgren syndrome, confirmed rather than assumed.