Dermatomyositis (overview) M33.-

Author: Prof. Dr. med. Peter Altmeyer

Co-Autors: Johannes Fritz, Lea Kiefer

All authors of this article

Last updated on: 29.04.2022

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Synonym(s)

Acute cases; acute parenchymatous; Dermatomucomyositis; imflammatory myopathies; Muscle inflammation; Muscle inflammation acute; Myositis; Myositis acute parenchymatous; Myositis universalis acuta infectiosa; Polymyositis; Pseudo-Trichinosis (Hepp); Purple Disease; Purple disease white spotted; Purple sickness; Wagner(-Unverricht)-Syndrome; white stained (Glanzmann)

History
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Wagner, 1863; Unverricht, 1887

Definition
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Rare, acquired, systemic, antibody- or immune complex-mediated group of autoimmune diseases with immunological reactions against vascular and muscle fiber proteins and diagnostically groundbreaking inflammatory skin manifestations. Furthermore, there are inflammatory atrophying vascular connective tissue reactions as well as segmental necroses of the striated musculature, which manifest themselves in a clinically usually clearly prominent muscle weakness.

Dermatomyositis, like other autoimmune myositides with other "collagenoses", can also occur as overlap syn dromes and, in association with malignant tumors, as a paraneoplastic syndrome(dermatomyositis, malignoma-associated).

Classification
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Clinically, a distinction is made (with frequencies):

  • Adult polymyositis (PM- without skin symptoms) 30% - is not seen dermatologically.
  • Adult typical dermatomyositis (DM - idiopathic dermatomyositis)/25%.
  • Dermatomyositis associated withmalignancy (CAM) /10%.
  • Dermatomyositis associated withcollagenoses (CTM - as part of an overlap syndrome/overlap group)/30%
  • Amyopathic dermatomyositis (ADM) (in adults and children)
  • Juvenile dermatomyositis (with vasculitis)/5%.

Occurrence/Epidemiology
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  • Incidence (juvenile dermatomyositis): 0.2/100,000 inhabitants/year.
  • Incidence (adult dermatomyositis): 0.6-1.0/100,000 inhabitants/year.
  • African-Americans are more frequently affected than Caucasians.

Etiopathogenesis
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Together with polymyositis and inclusion body myositis, dermatomyositis belongs to the group of inflammatory myopathies. Environmental factors, especially sun exposure, can lead to an exacerbation of dermatomyositis.

  • Genetic predispositions
    • exist for all idiopathic myositis in haplotypes HLA-B8, HLA DRB 03; HLA-A68 and HLA-DR3 for classic and juvenile dermatomyositis. For drug-associated dermatomyositis, HLA-B 08 and HLA-DR4 haplotypes were detected. No HLA associations are known for amyopahtic dermatomyositis.
  • Infections:
    • Aetiologically significant is the formation of antibodies against muscle antigens (AK against nuclear Mi-2 antigen, antisynthetase AK). Viral infections ( picornaviruses or coxsackieviruses) are discussed as a trigger mechanism. Antibodies to viral surface antigens may have structural similarity to nuclear antigens and induce antibody formation. In children, bacterial foci may also cause antibody formation.
  • A humoral immune mechanism has been described:
    • In this case, deposition of C5b-9 complement complexes on the endothelium of the skin and skeletal muscle occurs. For both polymyositis and dermatoymositis, there is an increased frequency of haplotypes with DR3, up to 75%. Dermatomyositis symptoms have been observed in congenital immunodeficiencies ("X-linked immunodeficency"/C9 defects), as well as in AIDS and HTLV-1 associated T-cell lymphomas (see below lymphoma, cutaneous T-cell lymphoma).
  • Medications:
  • Dermatomyositis as cutaneous paraneoplasia:
    • In 18-32% of pat.; mostly pat. > 50 years): Clustering in individual families. The relative risk of malignancy development is 2.4 times to 3.8 times higher than in the average population. The risk of tumor development is highest in the first year of diagnosis and decreases continuously in the following years. The most common tumors are ovarian carcinomas, gastrointestinal carcinomas, lung and breast carcinomas, prostate carcinomas, and non-Hodgkin lymphomas. In Asians, nasopharyngeal carcinomas are the most common. In juvenile dermatomyositis, the tumor association is absent.

Manifestation
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  • In the adult form there is gynecotropia: women are affected about 1.5-2 times more often than men. In adult dermatomyositis there are 2 peaks in frequency, 35-44 LJ and 55-60 LJ.
  • No sex preference in childhood (this statement is not found in other studies, here: F:M=6:1). First manifestation of juvenile dermatomyositis: Mostly 7-8th LJ.

Clinical features
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General: General fatigue with muscle weakness and muscle soreness. Patients can perform their normal activities (e.g., climbing stairs, combing hair) with difficulty or not at all.

Note: Patient appears tired at consultation, leans on chair when standing up, hand clasp is feeble, gait sluggish, voice quiet to broken.

Integument (often initial sign of dermatomyositis: skin manifestations precede muscle weakness in 1/3 of cases).

Initial stage: Initially, areal facial swellings with conspicuous eyelid edema, heliotrope, red to blue-violet, areactive but also pruritic or painful erythema and/or plaques that appear butterfly-shaped over the cheeks, expose a perioral zone, and heliotrope the neckline. Less common are blurred, patchy satin red erythema on the back. Specifically, the following phenomena are described:

  • Gottron's sign: Diagnostically significant are satin-red, streaky erythema and papules on the extensor sides of the fingers (= Gottron's sign in about 70% of patients).
  • Nail fold hyperkeratosis: (the attempt to push back the nail fold is very painful = Keining sign) with mega and tufted capillaries, elongated and torqued capillaries possibly with hemorrhages (capillary microscopy).
  • Heliotropic erythema:wine-red diffuse erythema is visibleespeciallyin the sun-exposed areas of the skin (face, eyelids, décolleté).
  • Perioral pallor: characteristic is the absence of erythema in the perioral region (thus the perioral region appears pale: perioral pallor).
  • V sign: confluent macular erythema spreading in a V shape over the lower anterior neck and upper chest region (appearances are often associated with anti-Mi-2 autoantibody).
  • Shawl sign: confluent areal erythema localized like a scarf tied around it.
  • Holster sign: red or red-purple planar erythema localized to the lateral thighs or hips in the shape of a worn gun holster.

Late stage: Variegated (poikilodermic) skin appearance due to brown-red discoloration of the lesions with sunken atrophic areas, sometimes also coarse sclerotic plaques with calcification processes (especially in children and adolescents). Often the skin changes are combined with diffuse effluvium .

  • Mechanic hands: hyperkeratotic cracked skin on the palmar and lateral aspect of the fingers.

Muscles: Increasing, symmetrical, painful (muscle soreness) muscle weakness, especially of proximal limb segments. Calcifications of the muscles are possible, rather rare in adults, up to 40% in children and adolescents (see below Dermatomyositis, juvenile).

Skeletal system: Arthralgias and arthritides occur in about 25% of patients with inflammatory muscle diseases. Partly type of symmetric polyarthritis, also as oligo- or monarthritis. Rarely mutilating arthritis (DD: antisynthetase syndrome; see overlap syndrome below). Further: Severe osteoporosis, more extensive calcification of soft tissues (tendons, muscles, aponeuroses), and significant joint deformities (joint space is preserved!).

Lung: Lung involvement (primary interstitial pneumonitis) in 15-30% of patients.

Vessels: Concomitant Raynaud's phenomenon or scleroderma-like edema (hands) suggest overlap syndrome. This symptomatology is rarely associated with malignant tumor.

Adipose tissue: Rare but clinically established manifestation of dermatomyositis with indurated, painful nodules or plaques on the abdomen, buttocks, and arms. Ulceration and lipodystrophy may occur.

Mucous membranes: ulcers of the oral mucosa in 10% to 20%.

Internal organs: involvement of heart, intestine and kidneys. Dysphagia due to weakness of oropharyngeal muscles. Associated: bronchopneumonia (aspiration due to dysphagia), hepato-splenomegaly, nephritis, tenderness of large nerve trunks, mental changes, focal retinitis peripapillosa, cotton-wool exudate, small streaky hemorrhages in the nerve fiber layer, papilledema, rarely episcleritis and scleritis.

Laboratory
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  • Serum: CK i.S. (especially MM type) increased up to 50-fold, aldolase, GOT, GPT, LDH increased. Creatinine excretion increased in 24h urine during the relapse.
  • Antibodies have an increasingly important role. A distinction is made between myositis associated antibodies (MAA) and myositis specific antibodies (MSA). Detection of antinuclear antibodies (ANA) in about 33% of cases is possible. An important indicator for dermatomyositis are antibodies against MI-2. Furthermore the following antibody profile is possible:
Autoantibodies Frequency (%) Clinical association

Myositis-specific autoantibodies (varies according to Volc-Platzer) DM = Dermatomyositis

Mi-2

20-30%

5%

Classic DM

Paraneoplastic DM

MDAS (CADM140) 50% Amyopathic DM
SAE 5-8% Adult DM
TIF1 (p155/140)

40-75%

20-25%

30%

Paraneoplastic DM

Adult DM

Juvenile DM

NXP-2 25% Juvenile dermatomyositis
t-RNA synthetases (e.g. Jo-1) 5-20% Antisynthetase syndrome
SRP 5% Adult dermatomyositis
MDA5 indicated pulmonary fibrosis or upcoming pulmonary fibrosis highly significant.

Myositis-associated antibodies (varied according to Volc-Platzer)

Autoantibodies Frequency% Clinical association
Ro (SSA) 19% Antisynthetase syndrome (Anti-Jo-1 syndrome
U1-RNP 8% Mixed connective tissue syndrome
PM/Scl (75-100kd) 2% Sclerodermatomyositis
Ku 1% Overlap myositis (overlap myositis)

  • Blood count: Lymphopenia, often marked eosinophilia, leukocytosis with left shift also occurs.
  • ESR: Moderate to moderate acceleration.
  • Serum electrophoresis: increase in alpha 2- and gamma-globulin.
  • Urine: creatinine and creatinineuria. Proteinuria in the episode, myoglobinuria.

Histology
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  • Integument: Uncharacteristic interface dermatitis of varying severity, possibly with mild acanthosis or atrophy with degeneration of the basal keratinocytes.
  • Electron microscopy: Tubulovesicular inclusions in the vascular endothelium.
  • Muscle: segmental muscle fibre necrosis, loss of transverse striation, eosinophilic granular necrosis, interstitial mononuclear infiltrate, possibly vascular alterations with intimal hypertrophy and fibrin deposits in the small arterioles. Relative reduction of CD4 T cells and lymphocytes.
  • Adipose tissue: Mixed septal/lobal panniculitis with dominating infiltrate of lymphocytes, plasma cells and focal membranocystic fat tissue necrosis. Lymphocytic vasculitis may occur.

Diagnosis
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  • Clinic
  • Histology and immunohistology from skin biopsy and muscle biopsy
  • Electromyogram: Short polyphase potentials, fibrillations
  • Creatine excretion in 24-hour urine
  • ANA in majority of patients low-titer positive
  • Myositis-associated AK are (in contrast to polymyositis) rather rare in dermatomyositis (Jo-1-AK, Mi-2-AK). In patients with AK against aminoacyl-t-RNA synthases, SRP or Mi-2, myositis is at the forefront of the disease. Jo-1-AK is of the greatest clinical importance (see below antisynthetase syndrome).
  • For the diagnosis "polymyositis" at least 3 of the following criteria should be positive:
    • Muscle enzymes (creatine kinase)
    • EMG
    • Muscle biopsy.
  • In many cases, the suspected diagnosis must be made solely on the basis of the clinical symptoms, as other parameters are inconsistent.

Differential diagnosis
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  • Systemic lupus erythematosus (mostly acute onset, absence of the Gottron sign; classical serology)
  • Acute contact allergic eczema of the face (flat "contact-related" eczema, possibly weeping (dermatoymositis never weeping), severe itching, no general complaints!)
  • Mixed connective tissue disease (serological clarification)
  • Rosacea erythematosa (At first glance, skin changes are quite similar. Accompanying follicular papules or even pustules exclude DM. Mostly nutritive or emotionally triggered flush phenomena. Never general complaints:-)
  • Dermatomyositis-like skin signs in case of infection by B. burgdorferi, in case of T-cell lymphoma, atopic eczema (serological and histological clarification of the underlying disease).
  • Trichinosis and cysticercosis (myalgias, fatigue, urticarial, often esosinophilic exanthema; marked blood eosinophilia. Eosinophilia would be unusual in dermatomyositis)
  • Myositides of other genesis (no dermatological component)
  • Thyrotoxic myopathy and muscular dystrophies (neurological clarification; the pioneering dermatological phenomena of dermatomyositis are missing).

General therapy
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  • tumour exclusion (especially ovary, lung, pancreas, colon, non-Hodgkin lymphoma) at least 1 time per year
  • Exclusion of bacterial foci, if necessary remediation.
  • In acute phases of illness, bed rest and general robotic measures.
  • Due to the long-term glucocorticoid treatment, recommendations such as a low-salt diet and fluid restriction and, if necessary, the substitution of calcium and vitamin D (Vigantoletten 1000 1Tbl./day) should be carried out in the case of beginning osteoporosis.
  • Physiotherapeutic exercises or physical measures to improve muscle function are also recommended.
  • Photoprotective measures are necessary for all variants of dermatomyositis.

External therapy
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Application of textile and chemical/physical light protection. In individual cases, a short-term, concomitant, low-dose therapy with topical glucocorticoids can be performed.

Internal therapy
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  • Glucocorticoids such as prednisolone (e.g. Decortin H) at a dosage of (at least) 1.0-2.0 mg/kg bw/day In the case of highly acute courses of disease, steroid pulse therapy at a dosage of 1 g/day for 3-5 days can be carried out initially. Continuation with prednisolone at a dosage of 1.0-2.0 mg/kg bw/day, depending on clinical symptoms. Fluorinated glucocorticoids (e.g. dexamethasone, triamcinolone) should be avoided due to their potential to cause myopathy.
  • To save glucocorticoids, combination therapy with azathioprine (Imurek) 1.0-3.0 mg/kg bw/day is recommended at an early stage. Slow dose reduction of the glucocorticoids (e.g. every 2-4 weeks by 5-10 mg/day) depending on the clinical findings down to a maintenance dose (10-15 mg/day), which usually has to be maintained for months to years. Under certain circumstances, the dose may have to be increased again if the clinical findings deteriorate. In addition to the clinical findings, follow-up examinations and activity determinations are carried out by determining the muscle enzymes (creatine kinase, aldolase, lactate dehydrogenase). An outlet test can only be attempted after several months of freedom from symptoms (normalisation of serum creatine kinase values). A prior determination of the thiopurine methyltransferase (TPMT) can be performed to assess genetic mis-metabolism. Contraindications: combination with Allopuriol!
  • Methotrexate (MTX) is an alternative to azathioprine. Start with 7.5-10.0 mg/week p.o. or i.v., increase in weekly steps of 2.5 mg up to a maintenance dose of 25 mg/week Cave! No i.m. injections, as the increase in muscle enzymes means that it is no longer possible to monitor the progress of the treatment!
  • Alternatively: cyclophosphamide (e.g. endoxane) 100-150 mg/day; also described as shock therapy at a dosage of 0.5-1.0 g/m2 KO/month i.v.
  • Alternatively (only case reports): Ciclosporin A (sandimmune) 3.0-5.0 mg/kg bw/day divided into two doses.
  • Alternatively (case reports only): Mycophenolate mofetil (CellCept) 2.0 g/day p.o. Similar effect as azathioprine (antipurine metabolite) with a start-up period of approx. 3 months.
  • Alternative: high-dose immunoglobulins (IVIG) in doses of 0.5-1.0 g/kg bw/day for 3 days i.v. (repeated every 4 weeks) especially in therapy-resistant active dermatomyositis patients. Intravenous immunoglobulin therapy ( IVIG therapy) has also proven to be effective in juvenile forms of dermatomyositis. Cave! Very high therapy costs!
  • Alternative: in case of insufficient response to glucocorticoids and IVIG, initiation of a therapy with Rituximab (Mabthera) 100-375 mg/m2 KO i.v. 4 times a week. Clear evidence for the success of this therapy is missing so far.
  • Alternative: In severe, therapy-resistant cases, plasmapheresis remains as the ultima ratio; confirmed results are still pending.
  • In current clinical studies: Eculizumab (anti-complement C5), tocilizumab (anti-interleukin-6), anakinra (anti-IL-1-receptor, see interleukin-1), gevokizumab (anti-interleukin-1beta), anti-interleukin-17 (see interleukin-17).

Progression/forecast
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Unpredictable development of the course. The duration of the disease varies (months to decades). In smaller cohorts, the 5-year survival rate was 95% and the 10-year survival rate was 84%. 50-75% of patients treated with immunosuppressants show significant improvement in clinical outcome. Older age and association with malignancy are associated with poor prognosis.

Note(s)
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In individual cases the dermatological phenomena of "dermatomyositis" are also observed without myositis, thus as minus varinates: "dermatomyositis sine myositis".

Literature
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  1. Bernard P, Bonnetblanc JM (1993) Dermatomyositis and malignancy. J Invest Dermatol 100:128-132
  2. Bruce H et al (2009) Cutaneous manifestations of internal malignancy. Cancer J Clin 59:73-98
  3. Callen JP, Wortmann RL (2006) Dermatomyositis. Clin Dermatol 24: 363-373
  4. Cherin P et al (1991) Efficacy of intravenous gammaglobulin therapy in chronic refractory polymyositis and dermatomyositis: an open study with 20 adult patients On J Med 91: 162-168
  5. Dalakas MC (2003) Therapeutic approaches in patients with inflammatory myopathies. Seminar Neurol 23: 199-206
  6. Dalakas MC (2003) Polymyositis and dermatomyositis. Lancet 57: 971-982
  7. Gardner-Medwin JM et al (2002) Incidence of Henoch-Schonlein purpura, Kawasaki disease, and rare vasculitides in children of different ethnic origins. Lancet 360: 1197-1202
  8. Gürcan HM et al (2009) A review of the current use of rituximab in autoimmune diseases. Int Immunopharmacol 9: 10-25
  9. Levine TD (2005) Rituximab in the treatment of dermatomyositis: an open-label pilot study. Arthritis Rheum 52: 601-607
  10. Mendez EP (2003) US incidence of juvenile dermatomyositis, 1995-1998: results from the National Institute of Arthritis and Musculoskeletal and Skin Diseases Registry. Arthritis Rheum 49: 300-305
  11. Moghadam-Kia S et al (2017) Modern Therapies for Idiopathic Inflammatory Myopathies (IIMs): Role of Biologics. Clin Rev Allergy Immunol 52:81-87.

  12. Mori H et al (2005) Relapse of dermatomyositis after 10 years in remission following curative surgical treatment of lung cancer. J Dermatol 32: 290-294

  13. Sato S et al (2005) Autoantibodies to a 140-kd polypeptide, CADM-140, in Japanese patients with clinically amyopathic dermatomyositis. Arthritis Rheum 52: 1571-1576
  14. Sunderkötter C et al (2016) Leitlinie Dermatomyositis - Extract from the interdisciplinary S2k guideline on myositis syndromes of the German Society of Neurology. JDDG 14: 321-333
  15. Tersiguel AC et al (2014) Prevalence of cancer in the Afro-Caribbean population presenting dermatomyositis and anti-synthetase syndrome: a preliminary study conducted at Pointe-à-Pitre University Hospital, 2000-2012 Ann Dermatol Venereol141:575-580

  16. Unverricht H (1887) On a peculiar form of acute muscle inflammation with a clinical picture similar to trichinosis. Münch med Wschr 34: 488-492
  17. Wagner EL (1863) Case of a rare muscle disease. Arch healing 4: 282-283

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Please ask your physician for a reliable diagnosis. This website is only meant as a reference.

Authors

Last updated on: 29.04.2022