Diagnosis

Temporal arteritis

Etiology

Cause [t61][bty][pya]

• Unknown

• Environmental/exogenous antigen: parvovirus, parainfluenza virus, varicella-zoster virus, Chlamydia pneumoniae, and Mycoplasma pneumoniae

• Genetic association with the HLA-DR4 haplotype and northern Europe

• Commonly associated with polymyalgia rheumatica

Pathophysiology [t61]

1. Activation of immune responses by presenting antigens --> T lymphocytes --> pro-inflammatory cytokines --> activation of macrophages and multinucleated giant cells:

   • Granulomatous vasculitis in medium- and large-sized arteries

2. Localisation:

   • Vertebral arteries, subclavian arteries, temporal/ophthalmic/occipital/ciliary arteries

3. Clinical manifestation:

   • Headache

   • Fever, malaise, depression, anorexia, and weight loss

   • Visual disturbances: scotoma

   • Jaw claudication, tongue pain

   • Musculoskeletal: Polymyalgia rheumatica (myalgia, stiffness)

   • Abnormal temporal artery biopsy

   • Upper extremity claudication, Raynaud phenomenon

   • CNS: Transient ischemic attacks or stroke

Complications [bty][pya]

• Permanent blindness

• Aortic aneurysm/dissection

• Stroke

• Tongue necrosis

• Glucocorticoid side effect

  • Cataract formation

  • Fragility fractures

  • Infection

  • Hypertension

  • Adrenal insufficiency

  • Diabetes

  • Osteoporosis

  • Osteonecrosis

  • Weight gain

Epidemiology

Incidence per 100.000 [f4t][sfc][bty][t61]

Approach

• Clinical diagnosis

• Blood tests: complete blood count, erythrocyte sedimentation rate, CRP, transaminases, blood glucose levels, creatinine kinase, aldolase, electrolytes, creatinine, calcium, phosphorus, albumin, alkaline phosphatase, 25-hydroxyvitamin D, and total protein [pya]

• Biopsy of the temporal artery

• Ultrasonography of the head, neck, and upper extremities

• Protein electrophoresis

• Urinalysis

• CT angiography

• PET-CT

GCA Classification Criteria

3 or more of the following parameters:

• Age ≥ 50 years

• New headache

• Tenderness or decreased pulsation of the temporal artery

• ESR ≥50 mm/h

• A temporal artery biopsy reveals vasculitis, characterized by a predominance of mononuclear cell infiltration, granulomatous inflammation, or multinucleated giant cells

Treatment

1. Prednisolone 40 to 60 mg/day for 2 to 4 weeks [bty][pya]

   • If impending danger of blindness --> IV methylprednisolone 1 g/day for 3 days

2. If clinical remission, decrease the dose to reach 20 mg/day and later 10 mg/day

3. Aspirin (81 mg) --> prevention of visual loss and stroke

4. Biologic agents: Tocilizumab (IL-6 inhibitor antagonist)

5. Management of dietary sugar, salt, and caloric intake

Differential diagnoses

Endocarditis, Microscopic polyangiitis, Optic neuritis, Polyarteritis nodosa, Polymyalgia rheumatica, Septic aortitis, Stroke, Takayasu arteritis, Transient ischemic attack, Wegener's granulomatosis