What is the diagnosis and treatment for a female with an autoimmune disease causing inability to comb hair and shoulder and arm pain?

Polymyalgia Rheumatica: Diagnosis and Treatment

The clinical presentation of a female with autoimmune disease causing inability to comb hair due to shoulder and arm pain is classic for polymyalgia rheumatica (PMR), which requires immediate corticosteroid therapy to prevent complications and restore function.

Clinical Diagnosis

The inability to comb hair is a pathognomonic symptom of PMR, reflecting severe bilateral shoulder girdle pain and stiffness that characteristically impairs activities of daily living 1. This autoimmune inflammatory condition predominantly affects women over 50 years and presents with:

• Bilateral shoulder and pelvic girdle pain and stiffness that is worse in the morning and after inactivity 1
• Functional impairment preventing basic self-care activities like combing hair, getting dressed, or rising from a chair 1
• Constitutional symptoms including fatigue, low-grade fever, and weight loss may accompany the musculoskeletal complaints 1
• Elevated inflammatory markers with ESR typically >40 mm/hr and often >100 mm/hr, plus elevated CRP 1

Differential Diagnosis to Exclude

Before confirming PMR, rule out other autoimmune conditions that can present similarly:

• Rheumatoid arthritis - look for small joint involvement, positive RF or ACPA, and symmetric synovitis 1, 2
• Systemic lupus erythematosus - check for malar rash, photosensitivity, oral ulcers, and positive ANA 1, 2
• Inflammatory myositis - assess for proximal muscle weakness (not just pain), elevated CK, and abnormal EMG 1
• Giant cell arteritis - screen for headache, jaw claudication, visual symptoms, and temporal artery tenderness, as this coexists in 15-20% of PMR cases 1

Essential Laboratory Workup

• ESR and CRP - both should be markedly elevated; normal inflammatory markers make PMR unlikely 1
• Complete blood count - may show normocytic anemia of chronic disease 1
• Comprehensive metabolic panel - to establish baseline before corticosteroid therapy 1
• Creatine kinase - should be normal in PMR (elevated in myositis) 1
• Thyroid function (TSH) - hypothyroidism can mimic PMR symptoms 1
• Rheumatoid factor and anti-CCP antibodies - to exclude rheumatoid arthritis 1

Note that autoantibodies are often absent in PMR, so negative results do not exclude the diagnosis 1.

Treatment Algorithm

Immediate Corticosteroid Therapy

Initiate prednisone 15-20 mg daily immediately upon diagnosis 1. The dramatic response to corticosteroids within 24-72 hours is both therapeutic and diagnostic - lack of rapid improvement should prompt reconsideration of the diagnosis 1.

Monitoring Response

• Expect significant symptom improvement within 1 week - patients should regain ability to perform activities like combing hair 1
• Recheck ESR/CRP at 4 weeks - inflammatory markers should normalize with adequate treatment 1
• Gradual taper over 12-24 months - reduce by 2.5 mg every 2-4 weeks once symptoms controlled, guided by clinical response and inflammatory markers 1

Screening for Giant Cell Arteritis

Actively screen for temporal arteritis symptoms at every visit, as this vision-threatening complication can develop during PMR treatment 1. Red flags include:

• New headache, especially temporal
• Jaw claudication with chewing
• Visual disturbances or sudden vision loss
• Scalp tenderness
• Tender, non-pulsatile temporal arteries

If any of these develop, increase prednisone to 40-60 mg daily immediately and obtain urgent temporal artery biopsy 1.

Screening for Associated Autoimmune Conditions

Women with autoimmune diseases require ongoing surveillance for additional autoimmune disorders 1:

• Thyroid function annually - autoimmune thyroiditis frequently coexists 1
• Fasting glucose and HbA1c - both for diabetes screening and to monitor corticosteroid effects 1
• Bone density (DEXA) at baseline and every 1-2 years - corticosteroids accelerate bone loss 1
• Vitamin D and calcium supplementation - initiate prophylactically with corticosteroid therapy 1

Common Pitfalls to Avoid

• Do not delay treatment waiting for specialist referral - PMR diagnosis is clinical, and corticosteroids should be started immediately to prevent functional disability 1
• Do not confuse PMR with fibromyalgia or mechanical shoulder pain - inflammatory markers are normal in these conditions, and they do not respond dramatically to corticosteroids 1
• Do not undertake extensive autoantibody panels - PMR is typically seronegative, and excessive testing delays appropriate treatment 1
• Do not miss coexisting giant cell arteritis - always ask about headache, visual symptoms, and jaw claudication at every visit 1
• Do not taper corticosteroids too rapidly - this leads to disease flare and prolonged treatment duration 1