Today we had an interesting case presented by Emilio. The case was a middle age patient with subacute oliogoarthritis and acute onset of fevers and a progressive painful papulopustular rash in the extremities ultimately found to have a new diagnosis of Behçet syndrome.
1) A pathergy test is performed by pinprick or injection of a small amount of intradermal NS; a positive test results in formation of a >2mm papule at the site in 1-2 days. The differential is quite short and includes Sweet syndrome, pyoderma gangrenosum and Behçet syndrome. 2) Behçet syndrome is a clinical diagnosis and one commonly used framework is from the International Study Group Criteria: the presence of recurrent oral ulcers and 2/4 of the following: (1) genital ulcers, (2) eye involvement, (3) skin involvement and (4) positive pathergy test. 3) A quick differential for a fever and rash is: infection, autoimmune process, malignancy and medication reaction
Ddx diffuse papulopustular rash
- Benign/ limited – think acne, folliculitis
- Infectious – disseminated zoster, disseminated HSV, endocarditis
- Autoimmune - vasculitis
- Malignancy – sweet syndrome (although usually see plaques or nodules)
- Drug hypersensitivity syndrome – DRESS, AGEP, SJS-TEN
OHSU computers have free VisualDx access, a great program to look up rashes and differentials. Also the VA gives you access to VisualDx as well. Go to Quick Hits -> and follow the link to set up a MyAthens account.
Ddx oral ulcers
- MCC: recurrent apthous ulcers
- HSV and other viral infections
- Medication reaction, eg SJS
- Autoimmune, eg Crohn’s disease, HLA-B27 related, pemphigus, SLE, behçet, sarcoid
Behçet syndrome is a rare pan-vasculitis involving vessels of all sizes and veins and arteries. Patients can have mucocutaneous ulcers (oral, genital), eye involvement (uveitis is classic), neurological (eg transverse myelitis, aseptic meningitis), thromboembolism, arthritis, GI involvement (similar to IBD), and pathergy. See this great review article from Nature Reviews Rheumatology for more details about diagnosis and management of behçet and differential for oral ulcers. Additionally, our very own Cailin Sibley has a great article in the Journal of Rheumatology about how it presents differently in the US (more GI and neuro symptoms).