Polyarthritis & Fever

Today was a case of polyarthritis & fever.

The pattern, timing, and associated symptoms of the polyarthritis will be key in narrowing the differential which includes:

- Rheumatologic conditions, specifically

Seropositive conditions: RA, MCTD, SLE, DM/PM

Seronegative condtions: AS, Reactive Arthritis (1st described in 1916 after Shigella dysentery in German officers), Psoriatic arthritis (often rash will appear after arthritis), and enteric arthritis

Systemic vasculitis

Crystal disease

- Infectious causes

Bacterial: Staph aureus, Group G strep, Neisserial infections

Tick borne disease ie Lyme disease (Borrelia burgdorferi)

Viral: Rubella, Parvo, HIV

- Drug related 

Serum sickness

This patient has a history of CAD, CHF, hypertension, hyperlipidemia, a. fib, gout, CKD, T2DM. He was on ASA, warfarin, bisoprolol, candesartan, glicliazide, lasix, and colchicine.

Gout can be precipitated by certain medications that cause hyperuricemia...think "CAN'T LEAP"

Cyclosporine

ASA

Nicotinic Acid

Thiazide

Lasix

Ethambutol 

Alcohol

Pyrazinamide

Remember that the ARB losartan actually has uricemic acid lowering properties.

Physical exam revealed symmetric painful and effusive joint disease affecting the shoulders, wrists, MCPs, PIPs, no DIP involvement, knees, and ankles.

Remember that 1st MCP and DIPs often in OA, 2nd MCP think of hemochromatosis, and wrist, MCP, PIP, knees, MTP's are the 5 most commonly affected joints in RA

Given the symmetric polyarthritis RA was considered the leading diagnosis. However, he did have proximal muscle weakness, which is not in keeping with RA, and raised the question of DM/PM or MCTD.

The diagnostic criteria for RA 4 out of 7 of the following, the first 4 greater than 6 weeks

1. Morning stiffness > 1 hour             5. RF positive

2. Arthritis 3 or more                        6. Rheumatoid nodules

3. Symmetric                                    7. Periarticular erosions 

4. Hand arthritis

At this time, diagnostic investigations are still pending.

Hopefully this provides an example and overview of polyarthritis and fever with some clinical pearls along the way.

Check out this review article on polyarthritis and fever from the NEJM. It is from 1994; however, it still provides a very nice general overview. Do keep in mind that certain aspects have since been updated.