What is the best course of treatment for an elderly patient with folliculitis, significantly elevated ESR, ferritin, and CRP, along with hyperlipidemia?

Urgent Evaluation for Adult-Onset Still's Disease

This patient requires immediate rheumatologic evaluation for Adult-Onset Still's Disease (AOSD), given the constellation of a rash, markedly elevated ESR (120 mm/h), and elevated inflammatory markers—a presentation that demands prompt diagnosis and treatment to prevent life-threatening complications.

Critical Diagnostic Considerations

Primary Concern: Adult-Onset Still's Disease

The clinical presentation strongly suggests AOSD based on:

• Markedly elevated ESR (120 mm/h) with elevated CRP (4 mg/dL), which are characteristic inflammatory markers in Still's disease 1
• Rash presentation initially appearing as "folliculitis" on the forehead—the salmon-colored evanescent rash of Still's disease can be misidentified and may not always present in its classic truncal distribution 1, 2
• Ferritin level of 170 ng/mL is elevated but not extremely high; however, this does not exclude AOSD, as ferritin levels vary widely in this condition 3, 4
• Microcytic indices (MCV 73, MCH 22.3, MCHC 30.8) with normal hemoglobin suggest chronic inflammation rather than iron deficiency, consistent with anemia of chronic disease seen in Still's disease 1

Immediate Diagnostic Workup Required

Obtain the following tests urgently:

• Serum ferritin with glycosylated ferritin fraction (if available)—extremely elevated ferritin (>1000 ng/mL, often >10,000 ng/mL) strongly supports AOSD diagnosis 3, 4
• IL-18 and/or S100 proteins (calprotectin) if available, as marked elevation strongly supports Still's disease diagnosis 1, 2
• Complete blood count with differential to assess for neutrophilic leukocytosis and thrombocytosis characteristic of Still's disease 2
• Liver function tests as elevated transaminases are common in AOSD 2
• Assess for fever pattern—document if patient has daily high-spiking fevers ≥39°C (102.2°F), which is a cardinal feature 1, 2

Critical Exclusions Before Diagnosis

Rule out alternative diagnoses that can present similarly:

• Malignancy (most common cause of markedly elevated ferritin in general populations) 4
• Infectious diseases including endocarditis, osteomyelitis, and occult infections 5
• Giant cell arteritis (ESR >40 mm/h has 93.2% sensitivity; critical in elderly patients) 5, 6
• Other autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus 6
• Hemophagocytic lymphohistiocytosis/macrophage activation syndrome (MAS)—a life-threatening complication that can occur at AOSD onset 1, 2, 3

Screening for Life-Threatening Complications

Macrophage Activation Syndrome (MAS)

Actively screen for MAS, which requires immediate recognition:

• Clinical features: Persistent fever, splenomegaly, inappropriately low cell counts (note patient has elevated RBC count, which argues against MAS currently) 1
• Laboratory markers: Rising ferritin, abnormal liver function tests, elevated triglycerides, intravascular coagulation markers 1
• This patient's thrombocytosis and elevated RBC count make active MAS less likely, but vigilant monitoring is essential 1, 2

Management of Hyperlipidemia

Address Cardiovascular Risk

The patient's lipid panel shows:

• Total cholesterol 259 mg/dL
• LDL 188 mg/dL
• HDL 51 mg/dL

Defer aggressive lipid management until inflammatory condition is controlled:

• Elevated ferritin and inflammatory markers can be associated with dyslipidemia 7
• Initiate statin therapy for LDL >190 mg/dL per standard cardiovascular risk reduction guidelines, but recognize that controlling the underlying inflammatory process may improve lipid parameters 8
• The elevated inflammatory state itself contributes to cardiovascular risk 7

Treatment Algorithm if AOSD Confirmed

Initial Management Strategy

If AOSD diagnosis is established, initiate treatment immediately:

• IL-1 inhibitor (anakinra) or IL-6 inhibitor (tocilizumab) should be started as early as possible when diagnosis is established 1
• Glucocorticoids may be needed initially but should not be used as monotherapy for prolonged periods 1
• Target resolution of fever and >50% reduction in CRP by day 7 1

Critical Pitfall to Avoid

Do not delay diagnosis waiting for arthritis to develop—arthritis is supportive but not necessary for AOSD diagnosis, and diagnostic delay can lead to serious complications including MAS 1, 2

Immediate Next Steps

1. Urgent rheumatology consultation for suspected AOSD 1
2. Repeat ferritin measurement and obtain IL-18/calprotectin if available 1, 2
3. Document fever pattern over next 24-48 hours 1
4. Screen for infections and malignancy with blood cultures, chest radiography, and age-appropriate cancer screening 5, 2, 4
5. Monitor for MAS development with serial CBC, liver enzymes, ferritin, and triglycerides 1, 2