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Sarcoidosis

ROUTINE — Systemic

Symptoms

  • blurred vision and floaters: common in intermediate or posterior involvement
  • ocular pain & photophobia: typically seen in acute anterior uveitis flares
  • dryness: "gritty" sensation due to lacrimal gland infiltration
  • systemic: chronic cough, shortness of breath, fatigue, and skin rashes
  • neuro: facial drooping (CN VII palsy) or unexplained headaches

Clinical Findings

Anterior segment

  • "mutton-fat" kps: large, greasy, yellow-white deposits on the corneal endothelium
  • iris nodules: koeppe (pupillary margin) and busacca (iris stroma) nodules
  • trabecular meshwork nodules: seen on gonioscopy; may cause "tent-shaped" synechiae

Posterior segment & vitreous

  • "string-of-pearls": inferior vitreous snowballs or opacities in a linear chain
  • "candle-wax drippings": segmental, waxy yellow perivasculitis (periphlebitis)
  • optic nerve: granulomas on the disc or significant disc edema

Adnexa

  • lacrimal gland enlargement: often bilateral and painless
  • conjunctival granulomas: small, yellow-pink "millet-seed" nodules in the fornix

Etiology

Pathophysiology

  • multisystem inflammatory disease involving non-caseating granulomas
  • the "great mimicker": can present as anterior, intermediate, posterior, or panuveitis

Demographics

  • bimodal peaks: ages 20–40 and 60–70; higher prevalence in African American and Northern European populations
  • blau syndrome: a rare pediatric genetic variant (NOD2) with uveitis, rash, and arthritis

Red Flags

  • neuro-sarcoidosis: optic nerve granulomas or cns involvement require immediate systemic steroids
  • cardiac sarcoid: must rule out fatal arrhythmias or heart block with an EKG/cardiology referral
  • candle-wax drippings: highly specific for sarcoid vasculitis; suggests active posterior disease
  • heerfordt syndrome: the triad of uveitis, parotid swelling, and facial nerve palsy

Investigations

Laboratory

  • serum ace & lysozyme: markers of total granuloma burden; often elevated in active disease
  • quantiferon-tb gold: mandatory to rule out TB before starting steroids (mimics sarcoid)

Imaging

  • chest ct (hrct): significantly more sensitive than CXR for hilar lymphadenopathy
  • gallium scan: may show the "panda sign" (uptake in lacrimal, parotid, and salivary glands)

Tissue diagnosis

  • biopsy: non-caseating granulomas from conjunctiva or skin is the diagnostic gold standard

Treatment

Local therapy

  • topical: prednisolone acetate 1% (frequently, e.g., q1h–qid) and cyclopentolate tid
  • periocular: sub-Tenon triamcinolone for unilateral macular edema or posterior disease

Systemic therapy

  • oral prednisone: 1 mg/kg/day for severe, bilateral, or neuro-involvement
  • steroid-sparing: methotrexate, mycophenolate, or adalimumab (Humira) for chronic control

Surgical

  • monitor for and treat secondary glaucoma and steroid-induced cataracts

Clinical Pearl

Sarcoid uveitis can involve any ocular structure — granulomatous KPs, candle-wax drippings, segmental vasculitis, and optic-nerve granuloma are all red flags; chest CT and ACE usually seal the diagnosis.

Differential Diagnosis

  • • ocular tuberculosis (caseating granulomas, positive TB test)
  • • syphilis (the other "great mimicker"; check treponemal antibodies)
  • • vkh syndrome (bilateral serous detachments, usually non-granulomatous)
  • • lymphoma (masquerade syndrome in older patients)

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