Myasthenia Gravis Overview
Myasthenia Gravis is an autoimmune disorder of the postsynaptic neuromuscular junction. Ab to AChR blocks receptor function, resulting in diminished muscle contraction. Associated with:
- Thymic tumors
- Paraneoplastic effects of SCC or Hodgkin lymphoma
- Autoimmune: thyroid, Sjogren syndrome, rheumatoid arthritis, SLE
Myasthenia Epidemiology:
- Bimodal age distribution in the 30s (female predominance) and 60s-70s (male predominance).
Clinical Picture of Myasthenia Gravis:
- Fatiguability: Worse towards the end of the day
- Fluctuating degree/variable degree of weakness in:
1. Ocular- 50%: Ptosis, diplopia
2. Bulbar- 15%: Dysphagia, dysarthria, hypophonia, fatiguable chewing, loss of smile
3. Neck: “dropping head syndrome”
4. Limb- proximal weakness, arms > legs
5. Respiratory muscles: “myasthenic crises”. Respiratory insufficiency and life-threatening
Differential DX:
- Thyroid ophthalmopathy
- Kearns-Sayre syndrome
- Myotonic dystrophy
- Brain stem/Cranial nerve pathology
- Generalized fatigue
- ALS
- Lambert Eaton myasthenia syndrome
- Miller Fischer and PCB variants of GBS
- Botulism
- Penicillamine induced myasthenia
Diagnosis - Clinical, Serologic and EMG Findings:
1. Clinical DX:
- Bedside: ice pack test/Edrophonium test
- Cogan sign
- Peek sign
2. Imaging - CT Chest: Evaluate for thymoma
3. Electrophysiologic Confirmation:
- Repetitive nerve stimulation
- Single fiber electromyography
4. Labs:
- AchR antibodies: first step in immunologic assay
- MuSK antibodies
- LRP4 antibodies
Myasthenia Gravis Treatment:
- Symptomatic Treatment: acetylcholinesterase inhibition
- Chronic Immunosuppressive Therapies: Steroids and NSAIDs
- Immunomodulating Treatments: IVIG and Therapeutic plasma exchange
- Surgical Treatment: Thymectomy
Myasthenia Crises - Severe bulbar weakness:
- Dysphagia and aspiration and acute respiratory failure
- Can be precipitated by: Drugs, infection, surgery, childbirth, tapering of immunosuppressants
- Meds to Avoid: Fluoroquinolones, Magnesium, Anesthetics, Penicillamine, Beta blockers, Procainamide
#Myasthenia #Gravis #diagnosis #management #neurology
Causes of Knee Effusions - Differential Diagnosis Framework
Knee Effusion Red Flags:
1. Fever/Chills/Joint pain/Night sweats/Weight loss
- DDX:
- Infection
- Systemic disease
- Malignancy
2. Non-weight bearing after injury
3. Loss of signal pulses
4. Loss of sensation distal to the knee
Infectious Knee Effusions - Septic Arthritis:
- Staphylococcal (40%)
- Streptococcal (28%)
- Gm - bacilli (19%)
- Mycobacterium (8%)
- Gm - cocci (3%)
- Gram + bacilli (1%)
- Anaerobes (1%)
- Watch out for:
- Gonorrhea
- Lyme’s disease
- Syphilis
- Tuberculosis
- Brucellosis
- Viruses: HIV, Chikungunya
- Herpes virus: CMV, HSV, Varicella, EBV
- Parvovirus
- Hepatitis B, C
- Rubella
- Alphavirus
- Fungi: Sporotrichosis, Coccidiomycosis, Candidiasis
Inflammatory Knee Effusions:
- Gout
- Pseudo gout
- Osteoarthritis
- Overuse syndrome
- Spondyloarthritis:
- Reactive arthritis
- Inflammatory bowel disease
- Rheumatoid arthritis
- Juvenile RA/Idiopathic arthritis
- SLE
- Behcet Disease
Post-Infectious Knee Effusions:
- Seronegative Reactive Syndrome
- Acute rheumatic fever
- Poststreptococcal reactive arthritis
Traumatic Knee Effusions:
- Ligamentous injuries
- Meniscal injury
- Intra-articulation fracture
- Patellar dislocation
Malignant Knee Effusions:
- Hematologic
- Leukemia
- Ewing’s sarcoma
- Giant cell tumor
- Osteosarcoma
- Eosinophils granuloma
- Synovial sarcoma
- Chondroblastoma
- Benign Tumors:
- Aneurysmal bone cyst
- Osteochondroma
Hematologic Knee Effusions:
- Hemarthrosis
- Hemophilia
- Synovium
- Oral anticoagulant therapy
- Sickle cell disease
Dr. Ravi Singh @rav7ks
#Knee #Effusions #causes #differential #diagnosis #msk #physicalexam
Cryptogenic Organizing Pneumonia (COP)
Cryptogenic Organizing Pneumonia Overview:
• Idiopathic form of organizing pneumonia
• formerly BOOP
• Type of interstitial lung that affects the distal bronchioles, alveolar ducts and walls.
• Secondary OP can be seen in association with CTD, drugs, malignancy and other interstitial pneumonias
Cryptogenic Organizing Pneumonia Epidemiology:
• Unknown
• 6-7 cases per 100,000 hospital admissions
• 56% of OP considered cryptogenic
Cryptogenic Organizing Pneumonia - Clinical manifestations:
• Onset: 5-6th decades of life
• History: cough, dyspnea, fever, malaise, weight loss of > 10 pounds
• Hemoptysis - rare
Cryptogenic Organizing Pneumonia - Imaging:
• CXR: Peripheral distribution of opacities, Unilateral consolidation and GG pattern, irregular lines, nodular opacities. Rare: pleural effusions, pleural thickening, cavities
• HRCT: patchy consolidation: peripheries and lower lung zone, GGO, small modular opacities, bronchial wall thickening with dilatation
Cryptogenic Organizing Pneumonia - Diagnosis:
• Lung biopsy: TBNA or Surgical lung biopsy
• Histopathology: Intraluminal plugs of inflammatory debris-small airways, alveolar ducts and adiacent alveoli
• Absence of histopathology suggestive of other processes
Workup / Laboratory Studies:
- No specific lab studies
- Make sure to order:
• CBC with diff
• Chem
• Transaminases
• UA
• Pneumonia: blood culture, sputum culture, urinary studies legionella/strep, HIV
• CTD workup: ANA, RF, CCP, CPK, anti-scl70, anticentromere ab, Anti-dsDNA, ANCA
COP DDX:
• CAP, Idiopathic interstitial pneumonia’s, Hypersensitivity pneumonitis, Granulomatous organizing pneumonia, Chronic eosinophilia pneumonia, Pulmonary lymphoma, Diffuse alveolar damage
Cryptogenic Organizing Pneumonia Treatment:
• Mild: observation
• Moderate: oral glucocorticoids
• Severe/ failure steroids: Cytotoxic Therapy
- Dr. Ravi Singh @rav7ks
#Cryptogenic #Organizing #Pneumonia #COP #BOOP #pulmonary #ILD #diagnosis #management
Elevated Transaminases / Transaminitis - Differential Diagnosis
• Infectious: HAV, HCV, HEV, EBV, HSV, CMV
• Neoplasm: Infiltration- often breast CA, small cell lung CA, lymphoma, melanoma, myeloma
• Congenital: HELLP
• Trauma: Shock liver
• Metabolic: Wilson Disease
• Vascular: Budd-chiari syndrome, Portal vein thrombosis, Sinusoidal obstruction syndrome
• Autoimmune hepatitis
• Iatrogenic: DILI, Tylenol, Mushroom poisoning
Dr. Ravi Singh @rav7ks
See Updated Schema Here: https://www.grepmed.com/images/10587
#Transaminitis #Elevated #Transaminases #hepatitis #Differential #Diagnosis #causes #hepatology
Lyme Disease - Diagnosis and Management Summary
Lyme Disease Epidemiology:
- Spirochete
- Reservoir: small mammals & birds
- Transmitted by Ixodes tick
- Ixodes Scapularis in eastern and north regions of North America
- Bimodal distribution:
- 5-14 years old
- 45-55 years old
- Peak incidence: Summer months
Lyme Disease Clinical Progression
1. Early Localized Disease:
- Erythema Chronicum Migrans
- Flu-like illness/fatigue
- Swollen lymph nodes
- Headache/stiff neck
- Sore throat
2. Early Disseminated - Weeks to Months:
- Neurological
- Carditis
3. Late Disease (Months to Years):
- Arthritis
- Neurological features
Lyme Disease Complications:
• Neuroborreliosis:
- Meningococcal-radiculitis
- Meningitis
- Meningo-encephalitis
- Bell’s palsy
- Vision changes
- Pain, weakness, numbness
• Carditis:
- AV block: Fluctuating first-second-third degree block
- Myopericarditis
- LV failure
- Pericarditis
• Ocular:
- Conjunctivitis
- Keratitis
- Iridocyclitis
- Retinal vasculitis
- Uveitis
• Neuro:
- Lyme encephalopathy
- Polyneuropathy
• Arthritis:
- Large joints
- Joint swelling/pain
Lyme Disease Diagnosis:
1. Rash: distinctive enough to make diagnosis if living in an endemic area
2. ELISA: detects antibodies to B. Burgdorferi
3. WESTERN BLOT: to confirm the dx. Detects antibodies to proteins of B. Burgdorferi
4. LP-CSF: lymphocytic pleocytosis
Lyme Disease Treatment:
1. Early: Doxycycline, amoxicillin 10-14 days
2. Early Disseminated: Doxycycline, amoxicillin or ceftriaxone for 14-28 days
3. Late:
- IV ceftriaxone, cefotaxime or PCN G for 21 days for Neuro involvement
- Oral doxycycline without Neuro disease
By Dr. Ravi Singh @rav7ks
#Lyme #Disease #Diagnosis #Management #treatment
Causes of Pseudocellulitis - Differential Diagnosis Framework for Cellulitis Mimics
Cellulitis: Deep skin and subcutaneous fat infection
Pseudo Cellulitis:
• Uncomplicated non-necrotizing inflammation of the dermis and hypodermis from a non-infectious etiology. However, many non-infectious entities can mimic cellulitis and must be differentiated.
• Imperative to diagnose to avoid unnecessary antibiotics and avoid allergic reactions, C. diff, change in host flora, and substantial health care spending.
• Early consult by dermatologists represents a cost-effective intervention and reduces inappropriate antibiotic use and hospitalization.
• Tetrad of key physical findings:
- Rubor, Dolor, Calor, and Rumor are non-specific markers of inflammation.
• Misdiagnosis as high as 28% in US hospitals.
Inflammatory Causes of Pseudocellulitis:
• Drug reaction
• Contact dermatitis
• Angioedema
• Sweet syndrome
• Gout
• Acute bursitis
• Erythema nodosum
• Pyoderma gangrenosum
• Sarcoidosis
• Eosinophilic cellulitis
• Panniculitis
• Polyarthritis nodosum
• Erythema migrans
Vascular Causes of Pseudocellulitis:
• Venous stasis
• Stasis dermatitis
• Lymphedema
• DVT
• Superficial thrombophlebitis
• Hematoma
• Erythromelalgia
• Calciphylaxis
• Superficial migratory thrombophlebitis
Neoplastic Causes of Pseudocellulitis:
• Lymphoma
• Leukemia
• Carcinoid erysipelas
• Inflammatory carcinoma - Lung, Pancreatic, GI
• Paraneoplastic
Miscellaneous Causes of Pseudocellulitis:
• Insect bites/stings
• Foreign body implant
• Coma bullae
• Compartment syndrome
• IV infiltration
By Dr. Ravi Singh @rav7ks
#Pseudocellulitis #Differential #Diagnosis #cellulitis #mimics #mimickers #Causes #dermatology #skin
