Lupus Nephritis

Shout out to Paige for admitting the interesting young woman with no medical history who presented with blurry vision, found to be in hypertensive emergency and nephrotic syndrome.  Her work up revealed diffuse proliferative lupus nephritis (class IV) without any other clinical features of lupus!


Clinical Pearls

  • Proteinuria is primarily caused by three processes: 1) overflow (due to elevated paraprotein levels), 2) glomerular disease, 3) tubular disease (rarely reaches nephrotic range)
  • Renal involvement is noted in ~50% of patients with SLE and can present as nephrotic and/or nephritic syndromes.
  • The most common and severe form is diffuse proliferative lupus nephritis (class IV)
  • Keep in mind that SLE flare is associated with a normal/low WBC, normal/low CRP, and absence of fever.  Infection, which can instigate a lupus nephritis flare, would cause an elevated WBC, elevated CRP, and fever.
  • Lab findings suggestive of SLE flare also include an elevated anti-dsDNA (correlates with disease activity), low complement levels (especially C3), worsening proteinuria, and elevated creatinine.
  • Treatment involves an induction phase with cytoxan or MMF plus solumedrol followed by a maintenance phase with the goal of reducing urine protein excretion to <0.33 g/day.

Hypertension urgency/emergency:

  • Urgency: BP>180/120 without end organ damage
    • Manage with orals, goal to lower (not necessarily correct) over 24-48 hours
  • Emergency: elevated BP + end organ damage (brain, eye, heart, kidney)
    • Manage with IV meds, reduce DBP by 10-15% over the first hour, then by 25% over the next 6-12 hours.
    • Special situations:
      • Lower rapidly in acute aortic dissection (goal SBP <110 ASAP)
      • Recent ischemic stroke: do not lower BP unless > 220/120 (> 185/110 if received reperfusion therapy)

Lupus

  • Female to male prevalence is 9:1
  • Diagnose using Systemic Lupus International Collaborating Clinics (SLICC) criteria.  Must have > 4 (at least 1 clinical and 1 laboratory) OR biopsy proven lupus nephritis with a positive ANA or dsDNA
  • Autoantibodies:
    • dsDNA is 50% sensitive but 97% specific –> can monitor disease activity
    • Smith is 10-20% sensitive but >90% specific
  • Work up of presumed flare:
    • Important to distinguish flare from acute infection but keep in mind that infection can trigger flare
    • SLE flare:
      • Low WBC and normal CRP (except when serositis is present)
      • Fever is unusual
    • Infection:
      • High WBC and high CRP
      • Fever is common 
  • Treatment:
    • Plaquenil for all unless contraindicated
    • Mild/mod:
      • plaquenil, NSAIDs, low dose steroids (pred 5 daily)
    • Severe
      • Acute: high dose steroids
      • Chronic: Immunosuppressive agents (MTX, cyclosporine, cyclophosphamide, azathioprine, mycophenolate, belimumab)
  • Prognosis
    • Worse with pediatric onset, ethnic minority, renal involvement, increased number of diagnostic criteria, low complement, e/o end organ damage
    • High association of CVD and SLE

SLE and renal disease

  • Renal involvement is common and eventually occurs in ~50% of SLE patients
  • 10% progress to ESRD
  • High mortality compared to SLE without nephritis
  • More common and severe in African Americans, Hispanics, Asians
  • Classifications of GN: can evolve from one to another
    • Minimal mesangial lupus nephritis (class I)
      • Earliest and mildest form
      • Rarely diagnosed b/c pts have a normal U/A, no or  minimal proteinuria, and normal Cr
    • Mesangial proliferative lupus nephritis (class II)
      • Microscopic hematuria and/or proteinuria
      • Light microscopy would show mesangial hypercellularity or mesangial matrix expansion
    • Focal lupus nephritis (class III)
      • Hematuria, proteinuria, some HTN, decreased GFR
      • Less than 50% glomeruli affected by light microscopy
      • Segmental glomerulonephritis
        • A: active lesions –> focal proliferative
        • A/C: active and chronic lesions –> focal proliferative and sclerosing
        • C: chronic inactive lesions and scarring –> sclerosing
    • Diffuse lupus nephritis (class IV)
      • Most common and most severe
      • Hematuria, proteinuria, nephrotic syndrome, HTN, reduced GFR
      • Hypocomplementemia (esp C3) and elevated anti-dsDNA during active disease
      • >50% of glomeruli are affected
    • Lupus membranous nephropathy (class V)
      • nephrotic syndrome, Cr normal or slightly elevated
      • Diffuse thickening of the glomerular capillary wall and subepithelial deposits
      • Can present without any other clinical or serologic manifestations of SLE
    • Advanced sclerosing lupus nephritis (class VI)
      • Slow, progressive renal dysfunction with proteinuria and relatively bland urine sediment
      • Global sclerosis >90% of glomeruli
      • Active GN no longer observed
  • Treatment:
    • Best to initiate early
    • Aimed at proliferative lupus nephritis
    • Induction
      • 3 – 12 months: goal is to obtain renal response.
      • Cytoxan or MMF PLUS solumedrol 250-1 g/day x 3 days (former takes 10-14 days to have an effect so the latter is much faster) or prednisone 60 mg/day
    • Maintenance
    • Response:
      • substantial reduction in urine protein excretion to <0.33 g/day
      • improvement or stabilization of serum creatinine
      • improvement of urinary sediment

Approach to glomerular disease:

Capture
* can be nephritic or nephrotic

Anti-Synthetase Syndrome 1/8/2019

Jonathan presented a case of a 39yo M with no significant medical history, presenting with 1 month of non-improving dry cough, dyspnea on exertion, subjective fevers, and leg weakness. His CK was significantly elevated on admission to 27k, and CXR revealed peri-hilar lung base opacities which could represent pneumonia. His exam was significant for debilitating proximal muscle weakness (distal strength was intact!) with hyporreflexia. Ultimately Anti-Jo1 antibodies returned positive, and CT Cx revealed predominantly lower lobe GGO without evidence of honeycombing or traction atelectasis. This constellation of findings (myopathy, lung pathology, anti-synthetase antibody positivity) is consistent with Anti-synthetase syndrome!


Anti-synthetase syndrome

Epidemiology

  • Up to 30% of patients with DM or PM will have this constellation of clinical findings, terms Anti-Synthetase syndrome.
  • More acute onset of the following:

Presentation: Often acute

  • Constitutional symptoms i.e. fever
  • Myositis
  • Raynaud’s phenomenon
  • Mechanic hands
  • Non-erosive arthritis
  • ILD: Often severe and rapidly progressive, frequently predominates other symptoms
  • Cardiac arrhythmias or ventricular dysfunction

Diagnosis

  • Poorly defined as a condition, but in general, diagnostic criteria based on expert consensus is positive antisynthetase antibodies plus at least 1 feature
  • Antibodies:
    • Antibodies to aminoacyl-rRNA synthetases (antisynthetase antibodies), i.e. Anti-Jo1 (most common)
    • Anti-PM-Scl
    • Anti-U1 RNP
    • Anti PL-7 & PL12 (seen in pts with predominantly ILD sx, often very severe)
    • If antiRo or ANA present, suspect more of an myositis associated ILD
  • CT:
    • Most common findings are traction bronchiectasis, GGO
  • Diagnosis usually is made by combination of CT findings, serology, PFT, and clinical findings.

Antibodies.png

Management

  • Often requires multiple immunosuppressives for symptomatic control.
  • First line: Corticosteroids, monotherapy associated with more frequent lung disease recurrence
  • Other agents often added i.e. azathioprine, mycophenolate, tacrolimus, rituximab, cyclophosphamide.

meds

Monitoring

  • Chronic steroids: osteoporosis, PJP prophylaxis if > 20mg > 1 month
  • Hep B reactivation
  • Azathioprine: Check TPMT levels!

 

Prognosis

  • Not associated with inc risk of malignancy
  • Anti PL7 and PL12 are associated with more aggressive ILD, and worse prognosis.
  • Presence of Anti-Jo1 and arthritis/myositis are actually good prognostic indicators.
    • Single center study: 10 year survival for Anti-Jo1 was 70%, vs 49% for non-Jo1

Myasthenia Crisis Secondary to… a Thymoma! 12/26/2018

Our case today is a 49 year old woman with no medical history, presenting with 1 month of difficulty swallowing, voice changes, and more recently dysphagia with liquids and solids, and shortness of breath. Her symptoms are worse during the night time to the point that she couldn’t swallow her own spit/secretions. She presented with respiratory failure requiring intubation, and on CXR/CT she was found to have an anterior mediastinal mass concerning for a… thymoma!


Let’s first briefly review Myasthenia Gravis before moving onto Myasthenia Crisis, and lastly, Thymomas.

Myasthenia Gravis

Epidemiology

  • Bimodal: Early peak in 2-3rd decades (female predominance) and late peak 60-80s (male predominance).
  • F in post-partum period have inc risk.
  • Possible association with: neuromyelitis optical, autoimmune thyroid disorders, SLE, RA.

Diagnosis

  • Bedside
    • Ice-pack test: Improvement of ptosis after application of an ice pack = positive. Sensitivity around 80ish %, limited to patients with ptosis and not helpful for those with extraocular muscle weakness.
      • myastheniagravis-myasthenia-diagnosis-clinical-icepack-original.jpeg Source: NEJM, Grepmed
    • Edrophonium test is no longer used very often, in a nut shell, it is a Acetylcholinesterase inhibitor with rapid onset (within 30-45 seconds), produces improvement of affect muscles after injection.
      • 80-90% sensitivity but high rates of false positive. Not very specific.
  • Serology (seropositive in 90% of MG patients).
    • AChR Ab
      • Titers do not correlate with disease activity
      • 85% positive in generalized MG
      • Highly specific, extremely low false positives (LE, certain motor neuro dz, polymyositis)
    • MuSK-Ab
      • Seen in 38-50% with generalized MG who are AChR Ab negative.
    • Thymoma patients with MG: 98-100% will have positive AChR-Ab.
      • NPPV for thymoma in the absence of AChR-Ab is 99.7%
    • Seronegative: 6-12%, more likely to have purely ocular myasthenia.
  • EMG: Can help confirm diagnosis
    • Single fiber EMG
      • Abnormal in > 90% of those with generalized MG, less so in ocular MG
      • Most sensitive diagnostic test for MG, 90-95% sensitivity (les for ocular MG), 91% specific.
    • Repetitive nerve stimulation
      • Readily available but less sensitive vs SFEMG
      • Nerve is stimulated multiple times, and the compound muscle action potential is recorded, test is considered positive if progressive decline in CMAP readings with the first 4-5 stimuli.
      • Sensitivity 75-80%

Management

  • Symptomatic: Pyridostigmine, max daily dose 7mg/kg
    • Too much pyridostigmine can cause cholinergic crisis, leading to—weakness. Chances of this dec by limit daily dose of pyridostigmine to less than 960mg daily
  • Chronic immunotherapy: Required for those with sx on pyridostigmine or recurrence of sx on pyridostigmine after initial improvement.
    • Steroids or immunosuppressives i.e. azathioprine, mycophenolate, cyclosporine.
  • Thymectomy: Recommended for age < 60, has been considered beneficial even without presence of a thymoma.

Myasthenic Crisis

Definition: Weakness severe enough to impair muscles of respiratory requiring mechanical ventilation.

  • 10-20% of pts with MG will experience at least one crisis, annual risk 2-3%
  • For 13-20% of pts with MC, the crisis is their first clinical manifestation of MG and initial diagnosis.
  • Most occur in the first few years after diagnosis of MG.

Presentation

  • Progressive generalized or bulbar weakness leading to respiratory failure.
  • Variable presentation in terms of degree of weakness (general vs respiratory)
  • May be precipitated by: infection, surgery, pregnancy, childbirth, medication tapering, certain drugs (beta blockers, antibiotics), magnesium

Evaluation

  • Airway/Breathing: Monitor respiratory muscle strength frequently, should be admitted to MICU
  • Indications for intubation:
    • FVC < 15 – 20 mL/kg
    • NIF < -25 to -30 cmH2O (i.e. 0 to -24)
    • Respiratory fatigue
    • PCO2 > 50
    • Difficulty with secretions

Management

  • Intubation if signs of impending respiratory failure.
    • Elective intubation, rather than emergent, is preferred.
  • Rapid IVIG or plasma exchange, FAST
    • Plasmapheresis directly removes acetylcholine receptor ab in the circulation
  • High dose glucocorticoids, azathioprine, cyclosporine, or mycophenolate
  • Wean as respiratory muscle strength improves after completing or IVIG or plasma exchange.
  • Aggressive pulmonary toilet.
  • Pyridostigmine generally avoided after intubation temporarily since it might increase secretions, leading to more complex pulmonary care.
    • Can be resumed after extubation.

Thymoma

Epidemiology

  • Median age 40-60
  • Men ~ Women
  • No known risk factors but strong association with myasthenia gravis

Presentation

  • Local thoracic symptoms
  • Asx
  • Paraneoplastic symptoms
  • Up to ½ of pts with thymoma will have MG like sx.
  • MG is common with thymomas but rare in thymic carcinoma

Paraneoplastic presentation

  • Neuro: MG, polymyositis, Lambert Eaton, Isaac’s syndrome, stiff person syndrome
  • Heme: Pure red cell aplasia, hemolytic anemia, pernicious anemia, agranulocytosis
  • Derm: Alopecia areata, pemphigus, scleroderma, vitiligo, oral lichen planus
  • Endo: Addison’s disease, Cushing syndrome, panhypopit, thyroiditis
  • Other: Nephrotic syndrome, RA, sarcoid, hepatitis, hypogammaglobulinemia, myocarditis

Diagnosis

  • CT and/or MRI
  • Carcinoma findings: Necrotic, cystic, or calcified, irregular contour
  • Definitive dx requires tissue biopsy

Staging

  • Masaoka staging system vs American Joint Committee on Cancer (AJCC), with the former being more commonly used.

Capture.JPG

Management

  • Surgical resection: as much as possible, including complete resection of the thymus. Potentially curative.
  • If extensive disease, can consider chemo followed by radical resection +/- RT for potentially resectable cases.
  • If complete resection cannot be done, maximal debulking followed by post-op RT.
  • Potential phrenic nerve damage due to tumor expansion or surgery. Can sacrifice one for surgical resection but if both are involved, then it’s a more complicated discussion.

Prognosis

  • Main determinant = staging and complete resectability of the tumor
  • Most commonly used staging system = Masaoka Staging System
  • Masaoka stage I and II: Favorable
  • Masaoka stage III: 27% recurrence after complete resection, 62% with incomplete resection. 10yr survival 83%
  • Masaoka stage IV: 10-yr survival is 47%

Leukocytoclastic vasculitis

Today, we talked about the case of a middle-aged man with history of diabetes, HTN, and A fib who presented with acute onset of progressive painful palpable purpura on his extremities, found to be cutaneous small vessel vasculitis on skin biopsy!


Clinical Pearls

  • Purpura implies problem at the level of vessel.  It can be divided into
    • Non-palpable purpura: petechiae (<3mm) or ecchymoses (>3 mm) and are usually associated with disorders of coagulation and platelets.
    • Palpable purpura: suggests inflammation and possible vasculitis.

Nomenclature:

  • Cutaneous small vessel vasculitis: disease limited to skin without any systemic vasculitis or glomerulonephritis
  • LCV: histopathologic term defining vasculitis of small vessels
  • Hypersensitivity vasculitis: small vessel necrotizing vasculitis
  • Immune complex small vessel vasculitis: associated with immune complex and/or complement deposition. If limited to skin, this is identical to cutaneous small vessel vasculitis. If not limited to skin, then other etiologies like cryo, SLE, Sjogren, RA, anti-GBM, IgA, etc.

Approach to purpura

Approach to purpura

  • Hypersensitivity (in the normal complement category of vasculitis) can result from medications/drugs as well as certain conditions such as HIV.
    • Numerous meds can cause LCV including some common ones such penicillins, cephalosporins, sulfonamides (including most loop and thiazide-type diuretics), phenytoin, and allopurinol have been most often implicated

Cutaneous small vessel vasculitis:

Clinical presentation:

  • Palpable purpura
  • + petechiae
  • Lesions can coalesce, ulcerate or be surrounded by hemorrhagic bullae
  • No visceral organ involvement in CSVV. However, it can occur later in the disease course.

Diagnosis:

  • Start with checking serum complement levels to guide your need for further laboratory work up!
  • Skin biopsy

Management and Prognosis:

  • Usually self limited and resolved within 2-4 weeks
  • If uncomplicated:
    • NSAIDs
    • Antihistamines
    • Rest, elevate, compression stockings
  • If complicated (presence of hemorrhagic blisters, cutaneous necrosis, or ulceration can lead to secondary infections, chronic wounds, and scarring)
    • Systemic glucocorticoids (oral steroids): pred 0.5 mg/kg of ideal body weight until new lesion formation ceases, then taper over 3-6 weeks
    • If relapse with prednisone: then colchicine or dapsone
    • If refractory: then azathioprine, methotrexate, and MMF

Example of palpable purpura with hemorrhagic blisters:

LCV skin example

Acute Rheumatic Fever

Today, we talked about the very interesting case of a middle-aged man who presented with acute migrating oligoarthritis, found to be febrile with an inflammatory synovial fluid and elevated ASO titers consistent with acute rheumatic fever!


Clinical Pearls

  • Nonsuppurative manifestations of GAS infection include acute rheumatic fever (ARF), acute GN, and Scarlet fever.
  • Use the modified Jones Criteria to help you diagnose ARF and treat early if high suspicion for the disease (do not wait for titers to come back).
  • Late complications of ARF include rheumatic heart disease (10-20 years after infection) and Jaccoud arthropathy.
  • Treatment of ARF involves NSAIDs for arthritis, PCN G IM x 1 dose for acute presentation and then monthly for prophylaxis, and patient education about oral hygiene to prevent endocarditis and need for prophylaxis before invasive procedures.

Differential diagnosis for a migratory arthritis

  • Rheumatic fever
  • Infective endocarditis
  • Vasculitis (IgA, cryo, ANCA associated)
  • SLE 
  • Acute leukemia
  • Serum sickness
  • Viral arthritis
  • Bacteremia (staph, strep, mening/gonococcal)
  • Pulmonary infections (mycoplasma, histoplasma)
  • Lyme
  • Whipple’s

Nonsuppurative complications of GAS infection

  • ARF
  • Scarlet fever
  • Acute GN

Rheumatic fever 

  • Nonsuppurative sequela that occurs 2-4 weeks after GAS pharyngitis
  • Epi
    • More common in children 5-15 years of age
    • More common in resource limited settings
  • Pathogenesis:
    • Poorly understood, ?molecular mimicry
  • Clinical manifestations:
    • Two primary manifestations of disease

Two manifestations of ARF

(Table above from UpToDate)

  • Late sequelae
    • Rheumatic heart disease (10-20 years after infection), primary involves the mitral valve >aortic valve.
      • Leading cause of cardiovascular death in the first 5 decades of life in resource limited settings
    • Jaccoud arthropathy
  • Diagnosis:
    • Revised Jones criteria (joint and cardiac manifestations can only be counted once).
      • Major
        • Carditis and valvulitis (clinical or subclinical) – 50-70%
          • Usually pancarditis. Valvulitis especially of mitral and aortic valves, shown as regurg on echo.
          • Carey Coombs murmur: short mid-diastolic murmur heard loudest at the apex
        • Arthritis (migratory, involving large joints) – 35-66%, earliest symptom
          • Several joints affected in quick succession, each inflamed for a day or two to one week. Most common are knees, ankles, elbows, and wrists.
        • CNS involvement (Sydenham chorea) – 10-30%
        • Subcutaneous nodules – 0-10%
        • Erythema marginatum – <6% 
      • Minor
        • Arthralgia
        • Fever >38.5
        • Elevated acute phase reactants (ESR, CRP)
        • Prolonged PR interval on EKG
      • Diagnosis requires evidence of prior GAS infection plus:
        • 2 major OR
        • 1 major + 2 minor criteria OR
        • 3 minor criteria (only if patient has history of prior episode of ARF)
      • In a high prevalence setting, slightly modified criteria are used.
    • Labs:
      • Prior GAS infection through either
        • Throat culture
        • Positive rapid strep antigen test
        • Elevated or rising ASO titers
      • Treatment
        • Goals
          • Symptomatic relief of acute disease manifestations
            • Arthritis: NSAIDs
            • Carditis: if severe, heart failure treatments
          • Eradication of GAS
            • IM PCN G benzathine x 1
            • Contacts (throat culture test and treat if positive)
          • Ppx against future GAS infection to prevent progression of cardiac disease
            • PCN G IM once a month
            • For 5 years or until 21 years of age (whichever is longer)
            • If ARF with carditis and residual heart disease
              • 10 years or until 40 years, sometimes even lifelong
            • Education
              • Oral health
              • Ppx before any invasive procedures

Neurosyphilis? Wait… reactive arthritis!

Thanks to Tim for presenting the interesting case of a middle-aged man with h/o inadequately treated syphilis who presented with neck stiffness worse in the mornings, back pain, and blurry vision, admitted for presumed neurosyphilis.  Exam revealed inflammation of T2/T3 joints, L SI joint tenderness, and an inflamed R foot with dactylitis of the 3rd and 4th digits.  Further history revealed a recent gonorrhea/chlamydia for which he was treated and HLA B27 positivity consistent with reactive arthritis!  He was started on NSAIDs with significant improvement of symptoms.


Clinical Pearls:

  • Neurosyphilis is most commonly seen in HIV positive patients and can present at any time after infection.
  • Early neurosyphilis occurs within the first year after infection and involves the CNS, meninges, and vasculature
    • Neurosyphilis presents with posterior uveitis or pan-uveitis whereas reactive arthritis presents with anterior uveitis
  • Late neurosyphilis occurs >10 years after infection and involves the brain and spinal cord parenchyma
  • The four main spondyloarthropathies are ankylosing spondylitis, psoriatic arthritis, reactive arthritis, and IBD-related arthritis.
  • The genital pathogen most commonly associated with reactive arthritis is chlamydia trachomatis.
    • HLA B27 is positive in 30-50% of patients
    • Mainstay of treatment is NSAIDs
    • Disease typically lasts 3-5 months.

 

Syphilis

Clinical manifestations and treatment of different stages of syphilis

Neurosyphilis manifestations

  • Refer to this prior post
  • Early (w/n first year of infection)
    • CSF, meninges, vasculature
    • Symptomatic meningitis
    • Ocular syphilis (posterior uveitis, panuveitis)
    • Meningovascular syphilis
      • Arteritis of any sized vessel which can lead tostroke or spinal cord infarction
  • Late
    • Brain and spinal cord parenchyma
      • General paresis (10-25 years after initialinfection)
        • Progressive dementia
        • Psychiatric symptoms
      • Tabes dorsalis (>20 years after initialinfection)
        • CSF may be completely normal
        • Affects dorsal columns
        • Symptoms
          • Sensory ataxia
          • Argyll-Robertson pupil
          • Lancinating pains
  • Diagnosis
    • Non-treponemal tests (poor sensitivity but highspecificity)
      • VDRL
      • RPR
    • Treponemal tests
      • FTA-ABS
      • Syphilis EIA
    • In an HIV negative patient with suspectedneurosyphilis and a non-reactive CSF-VDRL, one can establish the diagnosis with
      • CSF lymphocytes >5 cells/microL
      • CSF protein concentration >45

Reactive Arthritis

  • Epimiology
    • Young adults, M:F equal
  • Typically follows GI or urogenital infections (several days to weeks after infection)
    • Chlamydia trachomatis (most common genital infection associated)
    • Yersinia
    • Salmonella
    • Shigella
    • Campylobacter
    • E coli
    • C diff
    • Chlamydia pneumoniae
  • Manifestations
    • Mono- or oligoarticular pattern of arthritis,often involving the lower extremities, sometimes associated with dactylitis and enthesitis
    • The triad of arthritis, urethritis, andconjunctivitis is only present in a subset of patients (formerly called Reiter’s syndrome)
    • Ocular manifestions: conjunctivitis, less frequently anterior uveitis, episcleritis, and keratitis.
    • Other: 
      • Skin: keratoderma blennorhagica, erythema nodosum
      • Circinate balanitis 
      • Nail changes resembling psoriatic arthritis
  • Lab
    • E/o of antecedent or concomitant infection
    • Elevated acute phase reactants
    • Positive HLA-B27 (present in 30-50% of patients)
    • Inflammatory synovitis
    • Imaging consistent with enthesitis or arthritis
  • Treatment
    1. Treat any ongoing concurrent infection
    2. NSAIDs (first line)
    3. Steroids (if refractory to NSAIDs)
    4. DMARDS (for chronic reactive arthritis)
    5. Anti-TNF (last resort)
  • Prognosis
    • Duration is typically 3-5 months
    • >6 months duration is considered chronic reactive arthritis
    • Most remit completely or have little active disease w/n 6-12 months after presentation
    • 15-20% may experience more chronic persistent arthritis

Mycoplasma Induced Rash & Mucositis (MIRM!) 10/24/2018

Ernest presented a case of a young woman, with no medical history, presenting with acute onset severe mucositis (eyes, mouth, urogenital) after a few days of viral prodrome and one day after taking azithromycin prescribed by her PCP. Her skin findings were almost non-existent and the bulk of her symptoms were isolated to the mucosa. Her presentation is consistent with a diagnosis of MIRM!


MIRM (Mycoplasma Induced Rash and Mucositis)

Epidemiology

  • 25% of patients with mycoplasma pneumoniae experience extra-pulm manifestations
  • Coined different terms, incomplete SJS, Fuchs Syndrome, MIRM
  • Mean age: Young (median 11-12 yo), male predominance.

Presentation

  • Universally will have some sort of prodrome: cough, malaise, fever preceding eruption of lesions by ~ 1 week.
  • Manifestations: variable, mucositis alone, prominent mucositis with sparse skin involvement. Skin involvement tends to be very rare and on the milder side, presenting as vesiculobullous, targetoid, papules, macules. Rarely morbilliform.
  • Majority of cases are severe mucositis alone.
  • Involvement: Oral (100%), ocular (92%), urogenital (78%)

Diagnosis

  • Clinical Dx
  • Mycoplasma IgM/IgG helps but their sensitivity and specificity are highly variable.

Management:

Supportive care (especially pain control, hydration/nutrition, infection prevention) plus treat the underlying cause (mycoplasma)!

  • Systemic corticosteroids (mixed data so generally not recommended first line)
  • IVIG (has been used in very severe cases))

Prognosis

  • Better than SJS/TEN, 81% will make a full recovery.
  • Blindness/residual visual impairment is possible but less common vs SJS/TEN

Key distinguishing features:

MIRM: Young, slight male preference, usually 7 days after infection, predominantly mucosal involvement, very little cutaneous involvement, better prognosis vs SJS/TEN.

SJS/TEN: Any age, female preference, usually 1-3 weeks after drug exposure, diffused skin involvement (Nikolsky sign) + mucosal involvement, more severe ocular manifestation.

Please refer to this review article for more background on this condition.