Treatment of Polymyalgia Rheumatica in Patients with Osteomyelitis

Initial Treatment and Steroid Dosing

The European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) recommend starting with low-dose oral prednisone (12.5 mg/day) combined with early methotrexate (7.5-10 mg/week) to minimize steroid exposure while adequately treating the polymyalgia rheumatica (PMR), given the infection risk from osteomyelitis 1
The EULAR/ACR guidelines suggest an initial prednisone dose range of 12.5-25 mg/day, with the lower end specifically intended for patients with relevant comorbidities and risk factors for glucocorticoid-related side effects 2, 3, 1
In patients with active infection like osteomyelitis, the minimum effective dose (12.5 mg/day) should be used rather than higher doses within the recommended range 1
Doses >30 mg/day are strongly contraindicated due to clear evidence of harm without additional benefit 3, 1

The guidelines recommend early introduction of methotrexate in patients with risk factors or comorbidities where glucocorticoid-related adverse events are more likely, and in those with a high risk for prolonged therapy 1
Methotrexate should be added at a dose of 7.5-10 mg/week orally from the outset, rather than waiting for treatment failure 1

Consider intramuscular methylprednisolone 120 mg every 3 weeks as an alternative if oral steroids pose unacceptable infection risk 3, 1
The dosing schedule for intramuscular methylprednisolone is: 120 mg IM every 3 weeks until week 9, 100 mg at week 12, and monthly injections thereafter, reducing by 20 mg every 12 weeks until week 48, and then reducing by 20 mg every 16 weeks until discontinuation 2, 3

Assess clinical response at 2-4 weeks; if inadequate improvement occurs, the PMR diagnosis should be questioned rather than escalating to high-dose steroids 2, 3
For patients responding appropriately, taper to 10 mg/day within 4-8 weeks, and once remission is achieved, reduce by 1 mg every 4 weeks 1, 5
Continue methotrexate throughout the taper to prevent relapse 1

Ensure the osteomyelitis receives appropriate antimicrobial therapy, and close monitoring for infection progression is essential 4
Doses >15 mg/day significantly increase infection risk and should be avoided 4

Do not use initial doses ≤7.5 mg/day as they are discouraged due to insufficient anti-inflammatory effect 3, 1
Never use doses >30 mg/day due to clear evidence of harm without benefit 3, 1, 4
Do not delay methotrexate initiation waiting for steroid failure—early introduction is key for steroid sparing in high-risk patients 1
Ensure bone protection with calcium 800-1000 mg daily and vitamin D 400-800 units daily for all patients on chronic glucocorticoids 4