62 - Dermatomyositis Flashcards
Have the characteristic rash of dermatomyositis but no clinical signs or symptoms of myositis
Clinically amyopathic dermatomyositis
Have the characteristic DM rash but no clinical signs or symptoms of myositis
Clinically amyopathic dermatomyositis (CADM)
_____% of patients have CADM
20
If not CADM, then the rest of patients with DM have
Classic dermatomyositis
CADM can be further subclassified into
Hypomyopathic CM
Amyopathic DM
Hypomyopathic DM is classified if one of these test results is abnormal
- Magnetic resonance imaging
- Electromyography
- Muscle biopsy
- Laboratory studies of muscle enzymes
CADM in which all the test results are normal
Amyopathic DM
Y/N: It has become clear that muscle histology and clinical findings can be defined that are specific to DM
No - cannot be defined
Three major criteria in Sontheimer’s proposed diagnostic criteria for cutaneous dermatomyositis
- Heliotrope sign
- Gottron papules
- Gottron sign
Violaceous erythema over the eyelids
Heliotrope sign
Papules overlying the MCP and IP joints
Gottron papules
Erythema overlying the knees, elbows, IP joints, olecranon processes, patellae, and medial malleoli
Gottron sign
Sontheimer suggested that a diagnosis of CADM could be made if _____ major criteria were present or _____ major and _____ minor criteria were present in addition to biopsy of at least one region showing histopathologic changes consistent with DM
2
1, 2
CADM is an important group to recognize because these patients appear to harbor the same risks for _____ as their classic counterparts
Systemic disease
Malignancy
DM has a bimodal distribution in the age of disease onset, occurring at two peaks, at _____ years and _____ years of life
5 to 14
45 to 64
DM triggers
Substantial ultraviolet exposure
Strenuous activity (for the patient with concurrent myositis)
Recent malignancy
There is often significant pruritus associated with affected skin, particularly on the _____, which may also be described as a “tightness” or burning or with other dysesthetic qualities such as crawling or tingling
Scalp
Characteristic cutaneous feature of affected skin in DM
Violaceous patches and plaques, varying from a bright pink to a deep violet color
Trunk involvement seen on the posterior neck, upper back, and shoulders, which may extend to the posterior upper arms
Shawl sign
Confluent violaceous erythema on the sun-exposed areas of the lower anterior neck and anterior chest
V-neck sign
Generally, (juvenile/adult) DM more characteristically displays atrophy and poikiloderma in classic areas of Gottron sign
Juvenile
Violaceous erythema ad poikiloderma on the lateral hips and lateral thighs
Holster sign
Hyperkeratosis and fissuring along the medial thumb and lateral second and third digits
Mechanic’s hands
Mechanic’s hands is a cutaneous clue to the possible presence of
Interstitial lung disease
Proximal nailfold involvement can be highly suggestive of
DM
Ulceration may be present in 30% of patients and often affects the skin over the _____ although it can be found anywhere
Extensor joint surfaces
Cutaneous ulceration in DM warrants concern for the presence of
Anti-MDA5 antibodies or
Malignancy
Ulcers have been correlated with the presence of _____, but this is likely through their association with anti-MDA5 antibodies
Interstitial lung disease
Symmetric violaceous patch across the midline of the hard palate
Ovoid palatal patch
Ovoid palatal patch is most frequently observed in the subset of patients with DM with
Anti-transcriptional intermediary factor 1gamma (TIF1-gamma)
Ovoid palatal patch could be confused with oral findings of discoid lupus or lichen planus, but their consistent localization to the _____ may aid in the diagnosis of DM
Center of the hard palate
Although _____ is often an important sign of activity, it can often be a sign of damage as well
Erythema
Distinctive and pathognomonic pattern composed of reticulated, sometimes atrophic white macules adjacent to erythema or telangiectasias
Red on white
The thin skin along the _____ is a frequent place to visualize the “red-on-white” pattern
Bitemporal hairline
This morphology is a very useful diagnostic tool because it does not seem to be associated with other connective tissue diseases
Red on white
Atrophy, hypopigmentation, hyperpigmentation, and telangiectasias
Poikiloderma
_____, as opposed to the “red-on-white”, is a late manifestation and is not diagnostically specific
Poikiloderma
Typically a late manifestation in the skin, subcutaneous tissue, fascia, or muscle and typically affects the trunk proximal extremities, or areas of previous disease activity
Calcinosis
Calcinosis occurs more rapidly after disease onset in (juvenile/adult) versus (juvenile/adult) DM
Juvenile
Adult
Calcinosis is most frequent on the _____ in DM, in contrast to systemic sclerosis in which _____ calcinosis is most frequent
Extremities
Digital
In both juvenile and adult DM, the presence of _____ antibodies is associated with an increased risk of calcinosis
Anti-nuclear matrix protein 2 (NXP-2)
Calcinosis is also commonly seen in the _____ subset, which as associated with known vasculopathy
Anti-MDA5
Reflects active disease in DM, typically affecting the buttocks, trunk, and proximal extremities
May progress to calcinosis or lipoatrophy
Panniculitis
Histopathology shows a _____ panniculitus but may have features of lupus panniculitis with lipomembranous changes or with septal thickening as in deep morphea
Lobular
Patients with _____ antibodies have a higher risk of alopecia, which commonly is severe and occurs early in the disease
Anti-MDA5
Has been recently found to be associated with anti-NXP2 antibodies and may predict more severe muscle disease
Subcutaneous edema
Most common pulmonary manifestation in DM and is a leading cause of morbidity and mortality
Interstitial lung disease
Pulmonary function tests show a
Restrictive disease pattern with a decreased forced vital capacity or a decreased diffusion capacity of carbon monoxide
Most common radiographic and histologic pattern in DM
Nonspecific interstitial pneumonia
Rare manifestation in DM
PFT revealing a disproportionately low diffusion capacity of carbon monoxide compared with a relatively normal FVC
Pulmonary arterial hypertension
Gold standard for the diagnosis of pulmonary arterial hypertension
Right heart catheterization
Myositis in DM typically presents as
Symmetrical proximal muscle weakness
Described as soreness or muscle tightness or burning, but muscles are not tender to palpation
Myalgia
Patients may note a hoarse or raspy voice (dysphonia) from _____ involvement
Cricoarytenoid muscle
May occur because of weak pharyngeal musculature
Dysphagia
Y/N: There is a high correlation between dysphagia and weakness of the anterior neck muscles
Yes
Distal muscle weakness in the hands, manifesting as difficulty opening jars or holding onto objects, more typically occurs late in disease or in patients with _____ antibodies
Anti-NXP2
Arthralgias are common in DM, reported in _____% of patients
30 to 40
Gastrointestinal involvement is an uncommon manifestation in juvenile DM, reported in _____% of juvenile patients with DM
4
Y/N: Cardiac involvement in DM is usually subclinical
Yes
May be a useful biomarker in detecting subclinical cardiac muscle involvement
Cardiac troponin I
DM is associated with malignancy in _____% of cases
10 to 20
Malignancies tend to occur within the first _____ of disease onset
1 to 2 years
Major antibody associated with malignancy
Anti-TIF1-gamma
DM is primarily an immune-mediated disorder with molecular and histologic evidence supporting a role for _____ immunity
Both innate and adaptive
Y/N: Myositis is not a requirement for the diagnosis of DM
Yes
A patient presenting with alopecia, cutaneous or mucosal ulceration, palmar erythematous papules, severe arthralgia or arthritis, and shortness of breath should trigger the clinician to consider
Anti-MDA5 DM
Patients with mechanic’s hands, arthritis, Raynaud phenomenon, and lung symptoms are at high risk of having
Antisynthetase disease
Patients with extreme myalgia, peripheral edema, and distal weakness should be ruled out for DM specifically with
Anti-NXP2 antibodies
Myositis-specific autoantibodies associated with DM
TIF1-gamma NXP2 MDA5 SAE Mi-2 Jo-1 Other antisynthetase antibodies (PL-7, PL-12, EJ, OJ, SRP)
Early in the course of the disease, _____ are reasonably sensitive biomarkers of muscle inflammation. However, mid to late in the course of myositis, their sensitivity decreases
Serum muscle enzymes
Electromyographic studies
Serum muscle enzymes
Creatine kinase Aldolase Lactate dehydrogenase Aspartate aminotransferase Alanine aminotransferase
To increase the sensitivity of detecting myositis in laboratory testing, the clinician should
Evaluate creatine kinase, aldolase, and LDH as a group
All muscle enzymes can be elevated after strenuous activity; in questionable cases, the enzyme levels can be rechecked after
10-14 days following the activity
Can be elevated with liver disease or hemolysis of the blood sample
Aldolase
AST and ALT
Will be elevated with hepatic injury but will not be elevated in myositis
Helpful addition to laboratory testing for myositis if hepatic sources are suspected
Gamma-glutamyl transferas
Serum ferritin is often highly elevated (>500 mg/dL) in _____ patients
Anti-MDA5
Sensitive indicator of myositis on MRI and correlates with creatine kinase levels
Muscle edema
If a muscle biopsy is necessary to confirm the diagnosis of DM, it has the highest yielded if performed within _____ of beginning any immunomodulatory therapy
2 weeks
Most common source of persistent disease skin activity
Skin over muscles or other organs
Y/N: Cutaneous DM often has discordant treatment response with the muscle disease, with recalcitrant skin disease continuing years after the muscle disease is in remission
Yes
In addition to a complete history and physical examination, routine age-appropriate cancer screening studies (_____), and relevant screening blood work (_____) as well as a urinalysis are indicated
Colonoscopy, mammogram, prostate examination
Complete blood count, renal and liver function tests
The manual muscle testing for a subset of eight muscle groups may be performed, which is a validated muscle test in which eight major muscle groups (_____) that are the highest yield in idiopathic inflammatory myopathies
Neck flexors Deltoids Biceps Wrist extensors Gluteus maximus Gluteus medius Quadriceps Ankle dorsiflexors
Serum muscle enzymes are checked _____ as biomarkers or myositis
At each visit
Found in both cardiac as well as regenerating skeletal muscle, so it is not a specific test, although it could be used as a screening test for cardiac involvement
Creatine kinase-MB
First line treatment of skin disease in DM
Photoprotection
Topical steroids
Hydroxychloroquine or chloroquine
Quinacrine
First line treatment of muscle disease in DM
Systemic corticosteroids
Second line treatment of skin and muscle disease in DM
Methotrexate
Mycophenolate mofetil
IVIg
Azathioprine
Although photoprotection is a key first step in management, up to _____% of patients with DM are actually minimally photosensitive, and as few as _____% may report disease exacerbation after UV exposure
60
20
First line treatment for myositis in combination with prednisone
Methotrexate
In patients with DM with suspected or diagnosed ILD, it is prudent to select a different agent than _____ because of its potential to induce acute pneumonitis and pulmonary fibrosis, thereby complicating the evaluation and management of ILD
Methotrexate
First-line oral agent when ILD is present
Mycophenolate mofetil
Most likely the single most effective agent for cutaneous DM
Intravenous immunoglobulin
Commonly used as maintenance therapy in the treatment of ILD associated with idiopathic inflammatory myopathies, typically after induction with cyclophosphamide
Azathioprine
Calcinosis remains one of the most formidable therapeutic challenges in the DM. _____ for localized lesions remains the most effective and definitive therapy
Surgical excision
