Sarcoidosis Flashcards
Define sarcoidosis.
Sarcoidosis is a chronic granulomatous disorder of unknown aetiology, commonly affecting the lungs, skin, and eyes. It is characterised by accumulation of lymphocytes and macrophages and the formation of non-caseating granulomas in the lungs and other organs.
- Although lungs and lymph nodes are involved in more than 90% of patients, virtually any organ can be involved.
- It has a bimodal age distribution with 2 peaks in the third and fifth decades.
- The clinical course is often heterogeneous and unpredictable.
What is the epidemiology of sarcoidosis?
- Prevalnce 5-64/100,000 and incidence of 1-35/100,000 worldwide
- Highest rates reported in northern European/Scandanavian and African-American individuals. Lowest rates are reported in Japan.
- It may occur at any age but is usually seen in adults under 50yrs
- Usually sporadic but familial in 4-10% of cases.
What causes sarcoid?
Unknown aetiology —> non-caseating granulomas with multinucleated giant cells in the centre. Contain mainly macrophages and T-lymphocytes; CD4 throughout and CD8 in the periphery. CD4 and cytokines (If-y, IL-2, IL-12) maintain and promote granuloma formation.
Could be due to… causes.
- genetic
- immunological
- infecious (e.g., viruses, Borrelia burgdorferi, Propionibacterium acnes, Mycobacterium tuberculosis, and Mycoplasma)
How is sarcoid commonly classfied?
According to organ/system involvement:
- Systemic sarcoidosis: multisystem involvement, sometimes with chronic fatigue
- Pulmonary sarcoidosis: lungs involved in >90% of patients; further classified into stages I, II, III, and IV
- Cutaneous sarcoidosis: plaques; lupus pernio
- Ocular sarcoidosis: anterior uveitis is most common
- Cardiac sarcoidosis: 5% of patients; various types of heart block; cardiomyopathy later in course; if pulmonary arterial hypertension occurs can be debilitating
- Neurosarcoidosis: <10% of patients; headaches; seizures
Multisystem involvement is characteristic, but pulmonary involvement usually dominates. Skin, eyes, and peripheral lymph nodes are involved in 15% to 30% of patients. Clinically significant involvement of spleen, liver, heart, CNS, bone, or kidney occurs in a few patients. Incidental diagnosis on routine CXR also occurs.
What are the risk factors for sarcoidosis?
- age 20 to 40 years for initial presentation
- FHx sarcoidosis
- Scandinavian origin
- female gender
- non-smokers
- black ancestry (US): uveitis
- Puerto Rican origin: lupus pernio
- European origin: erythema nodosum
What is Lofgren syndrome?
Type of sarcoidosis which most commonly affects Scandanavian, Puerto Rican and Irish people.
Good prognosis.
Presents as a combination of erythema nodosum, bihilar lymphadenopathy, joint pain.
What are the common symptoms of sarcoidosis?
- Non-productive cough
- Dyspnoea
- Chronic factigue
- Arthralgia (knees, ankles, wrist but no synovial thickening)
- Photophobia (uveitis)
- Red painful eye - uveitis causing superficial punctuate keratitis
- Blurred vision - uveitis
Uncommon: headache (neurosarcoidosis), low-grade fever, modest unexplained weight loss, chest wall pain (costochondritis)
What are the signs of sarcoidosis on physical examination?
- Wheezing (bronchospasm)
- Rhonchi (continuous low pitched, rattling lung sounds that often resemble snoring; bronchospasm due to airway hyperactivity)
- Lymphadenopathy (cervical, submandibular non-tender)
- Erythema nodosum (tender erythematous nodules on lower extremities)
- Lupus pernio (indurated plaques wih discoloration of nose, cheeks, lips and ears)
- Conjunctival nodules
- Facial palsy (uveoparotid fever i.e. uveitis/parotitis/facial palsy)
Uncommon: arrhythmias (atrial or ventricular), hepatomegaly
What investigations would you do for sarcoidosis?
History - exclude beryllium exposure (sarcoid has similar presentation to berylliosis)
- CXR, ECG, PFTs
- FBC, serum urea, creatinine, liver enzymes, serum calcium
- purified protein derivative of tuberculin (PPD)
Other:
- CT
- flexible bronchoscopy w/ transbronchial biopsy, bronchoalveolar lavage, skin biopsy, endobronchial US- transbronchial needle aspiration.
- Serum ACE, 24hr urine calcium, gallium-67 scan
What is the CXR staging used in sarcoidosis? What else might you see on CXR of sarcoidosis?
- Stage 0: normal
- Stage I: bilateral hilar lymphadenopathy
- Stage II: bilateral hilar lymphadenopathy plus pulmonary infiltrates
- Stage III: pulmonary infiltrates without hilar lymphadenopathy
- Stage IV: extensive fibrosis with distortion.
Also: hilar/paratracheal adenopathy with upper lobe predominance, bilateral infiltrates, pleural effusions (rare) and egg shell calcifications (v rare)
What would you see in FBC/urea/creatinine/LFT/serum calcium/PFTs/PPD of sarcoid?
- FBC - anaemia in 4-20% and leukopenia in 40%
- Serum urea may be elevated*
- Creatinine may be elevated*
- Liver enzymes - elevated- asymptomatic aminotransferase (AST and ALT) elevation possible
- Serum calcium - hypercalcaemia due to dysregulated production of calcitriol by activated macrophages and granulomas.
- PFTs - restrictive/obstructive mixed patter but help monitor disease (FVC)
- PPD - negative (partial to complete anergy in sarcoidosis secondary to depressed cellular immunity)
*
What do these investigations show in sarcoid?
CT/BAL/bronch biopsy/ACE/gallium-67scan
- CT scan - same as CXR but ground glass(=reversible) and cystic architectual distortion (=irreversible). Calcified hilar/mediastinal lymph nodes in patients with longstanding disease.
- Bronchoscopy - usually essential for diagnosis, shows non-caseating granulomas
- BAL (lavage) - BAL lymphocytosis, with CD4-to-CD8 ratio >3.5
- Serum ACE - quite unreliable but usually elevated
- galliium-67 scan - panda sign and lambda sign (panda = lacrimal+parotid gland uptake; lambda= parahilar, infrahilar,right paratracheal/azygos node)
Briefly, how do you treat ongoing sarcoid?
- If without progressive adenopathy then observe.
- If progressive then oral/inhaled corticosteroids(for 1-3months then taper).
- Second line agents are cytotoxics e.g. methotrexate/azathioprine/hydroxychloroquine (used as corticosteroid sparing agents)
What is Lofgren’s syndrome?
A type of acute sarcoidosis.
The triad of:
- ankle arthritis/periarthritis
- erythema nodosum
- bilateral hilar lymphadenopathy
Usually good prognosis and chronic disease unlikely. Treat with NSAIDs or prednisolone.
