🧴 TOACS FCPS Station · Malar Rash in Juvenile Dermatomyositis
📷 Clinical Photograph – Heliotrope/Malar Rash
🔍 Key clinical features:
- ✓ Erythematous to violaceous rash – periorbital and malar distribution
- ✓ Heliotrope rash – purple discoloration of eyelids (pathognomonic)
- ✓ Photosensitive – worsens with sun exposure
- ✓ Associated with proximal muscle weakness – Gower sign
- ✓ Gottron papules – may be present over knuckles, elbows, knees
📋 Clinical scenario (examiner prompt)
A 6‑year‑old boy is brought in with a reddish-purple rash on his face that has been present for 2 months. The rash involves the cheeks and upper eyelids, giving a purple (heliotrope) discoloration. He has also been climbing stairs more slowly and has had difficulty rising from a squat or from sitting on the floor (Gower sign). His mother reports he has been fatigued and has had muscle pain. On examination, there is also a scaly erythematous eruption over the knuckles and elbows (Gottron papules).
🧑⚕️ Examiner tasks · TOACS
1. Identify the diagnosis from the clinical image and context.
2. Describe the clinical features (heliotrope malar rash, Gottron papules, proximal muscle weakness, Gower sign).
3. Explain the underlying condition (juvenile dermatomyositis, vasculopathy, myositis-specific antibodies).
4. Discuss diagnosis and management (muscle enzymes, MRI, corticosteroids, methotrexate).
🎯 Expected answers (for examiners)
- • Diagnosis: Juvenile dermatomyositis (JDM)
- • Clinical features: Heliotrope rash (purple discoloration of eyelids/malar area), Gottron papules (erythematous, scaly papules over knuckles, elbows, knees), proximal muscle weakness (difficulty climbing stairs, Gower sign), photosensitivity, fatigue
- • Pathophysiology: Immune-mediated vasculopathy affecting skin, muscle, and GI tract; associated with myositis-specific antibodies (TIF1γ, NXP2, MDA5)
- • Diagnosis: Characteristic rash + proximal weakness + elevated muscle enzymes (CK, aldolase, AST, ALT, LDH) + MRI (STIR showing muscle edema) + EMG/muscle biopsy if needed
- • Treatment: High-dose corticosteroids (prednisone 2 mg/kg/day or IV methylprednisolone) + methotrexate (steroid-sparing); IVIG for refractory disease; sun protection; physical therapy
- • Complications: Calcinosis (delayed treatment), lipodystrophy, GI vasculitis (emergency), interstitial lung disease (anti-MDA5)
• Heliotrope: Purple/erythematous discoloration of eyelids and periorbital area
• Malar distribution: Cheeks, may spare nasolabial folds (unlike SLE)
• Photosensitive: Worsens with UV exposure
• Pathognomonic: Together with Gottron papules, highly specific for JDM
• Associations: Anti-TIF1γ (severe rash, lipodystrophy), Anti-NXP2 (calcinosis), Anti-MDA5 (ILD)
⚡ Quick FCPS‑style MCQ
A 6-year-old girl presents with a purple-red rash on the cheeks and eyelids, scaly papules over knuckles, and difficulty climbing stairs (Gower sign). The most likely diagnosis is:
A. Systemic lupus erythematosus B. Juvenile dermatomyositis C. Henoch-Schönlein purpura D. Kawasaki disease📌 Topic summary · Malar Rash in Juvenile Dermatomyositis
Heliotrope rash – periorbital/malar violaceous erythema
Gottron papules, proximal muscle weakness
Vasculopathy, muscle inflammation
Clinical + CK, MRI, EMG, antibodies
Corticosteroids + methotrexate
Calcinosis, ILD, lipodystrophy
| Feature | Juvenile Dermatomyositis |
|---|---|
| Age of onset | Peak 4-10 years |
| Heliotrope rash | Purple-red discoloration of eyelids and periorbital/malar area; photosensitive |
| Gottron papules | Scaly erythematous papules over knuckles, elbows, knees |
| Muscle weakness | Proximal (shoulders, hips); Gower sign, difficulty climbing stairs |
| Diagnostic studies | Elevated CK, aldolase, AST, ALT, LDH; MRI (STIR muscle edema); EMG; muscle biopsy (perifascicular atrophy) |
| Myositis-specific antibodies | Anti-TIF1γ (lipodystrophy), Anti-NXP2 (calcinosis), Anti-MDA5 (ILD) |
| First-line treatment | Prednisone 2 mg/kg/day + methotrexate 15 mg/m²/week |
| Refractory treatment | IVIG, mycophenolate, rituximab, JAK inhibitors |
| Complications | Calcinosis, lipodystrophy, GI vasculitis, interstitial lung disease |