From the Guidelines
Dermatomyositis is characterized by distinctive cutaneous manifestations, including heliotrope rash, Gottron's papules, and photosensitive rashes, which are managed with sun protection, topical and systemic corticosteroids, antimalarials, and immunosuppressants, as outlined in the treatment recommendations by 1. The cutaneous manifestations of dermatomyositis include:
- Heliotrope rash: a purplish discoloration around the eyes
- Gottron's papules: erythematous papules over the knuckles
- Photosensitive rashes on sun-exposed areas like the V of the neck, upper back (shawl sign), and shoulders
- Periungual erythema
- Cuticular overgrowth
- Poikiloderma
- Calcinosis cutis Management of these manifestations begins with sun protection, including broad-spectrum sunscreens and protective clothing. First-line pharmacological treatment includes:
- Topical corticosteroids for limited disease
- Systemic corticosteroids (prednisone 0.5-1 mg/kg/day) for more extensive involvement, as recommended by 1
- Antimalarials like hydroxychloroquine (200-400 mg daily) as steroid-sparing agents For refractory cases, immunosuppressants such as:
- Methotrexate (15-25 mg weekly)
- Mycophenolate mofetil (1-3 g daily)
- Azathioprine (1-2.5 mg/kg/day) may be necessary, as discussed in 1 Newer biologics like rituximab may be considered in severe cases, as mentioned in 1 and 1. These treatments target the underlying autoimmune inflammation that causes the skin manifestations. Regular monitoring for medication side effects and disease progression is essential, as dermatomyositis can be associated with internal malignancy in some patients, particularly adults.
From the Research
Cutaneous Manifestations of Dermatomyositis
The cutaneous manifestations of dermatomyositis, a type of idiopathic inflammatory myopathy, are diverse and can be debilitating. Some of the key cutaneous features include:
- Heliotrope rash
- Gottron's papules
- V-neck sign
- Shawl sign
- Cuticular overgrowth
- Photosensitivity
- Mechanic's hand
- Nail-fold bleeding
- Skin ulcer
- Vasculitis
- Flagellate erythema
Management of Cutaneous Dermatomyositis
The management of cutaneous dermatomyositis can be challenging, and a discordant response to therapy may exist between muscle and skin disease 2. Various therapeutic agents and treatment approaches have been described, including:
- Intravenous immunoglobulin (IVIG) 3
- Rituximab, a monoclonal anti-CD20 antibody 4
- Topical agents
- Systemic treatments, such as oral corticosteroids, low-dosage methotrexate, and hydroxychloroquine
Relationship between Cutaneous Manifestations and Autoantibodies
The cutaneous manifestations of dermatomyositis can be associated with specific autoantibodies, such as:
- Anti-Mi-2 antibody, which is associated with classic features of DM, including heliotrope rash and Gottron's papules 5
- Anti-transcriptional intermediary factor 1 gamma (TIF1γ) antibody, which is associated with diffuse photoerythema and "dusky red face" 5
- Anti-melanoma differentiation-associated gene 5 product (MDA5) antibody, which is associated with skin ulcerations, palmar papules, and diffuse hair loss 5
Diagnostic Considerations
The diagnosis of dermatomyositis can be challenging, and skin biopsy can be useful for differential diagnoses 6. The presence of multiple types of eruptions can help diagnose the disease, and correct evaluation of cutaneous manifestations and myositis-associated autoantibodies can aid in early diagnosis 5.