A report describes a case of an 8–year–old African girl who presented with an 8-week history of recurrent fever, followed by a skin rash, weakness of all limbs, and generalized body swelling two weeks later. She had a low-grade fever, accompanied by a sore throat, for which she received antibiotics and antimalarial. Still, it recurred with no specific periodicity throughout her illness. 

Her rash was maculopapular and itchy, which started on the upper extremities (arms, hands, and predominantly on the knuckles) and progressed to involve the thighs. It lasted for two weeks and persisted in the knees as papules and painful ulcerations on the flexure areas of the limbs. She then developed limb weakness, which was progressive and symmetrical, involving the proximal aspects of her upper and lower limbs and interfering with her movement. She also described muscle and joint pain and swelling on the face, which was more prominent around the eyes. 

She reported a nasal tone to her voice during illness but no history of dysphagia. All other histories were insignificant.

Physical examination showed her to be afebrile and in pain, with generalized edema (periorbital and bilateral nonpitting edema of upper and lower limbs) and normal body mass index. 

Local examination showed hyperpigmented macules located on both knees, anteriorly more on the right; some coalesced to form patches on the knuckles (Gottron′s sign). Additionally, there were hyperpigmented patches and ulcers with clear, crusted border margins measuring about 2 cm posterior to the knees and axillary folds. 

The patient showed a tiptoe gait with limited extension and flexion of the knees and ankle joints. Her grip power was normal, with limited movements of the elbows and shoulder joints. There were no joint swelling, warmth, or spine deformities. 

She had normal muscle bulk, generalized tenderness in all muscle groups, and a reduced power of grade 3/5 in proximal muscle groups of the upper and lower limbs with a positive Gowers′ sign and no calcinosis cutis. Her Childhood Myositis Assessment Scale (CMAS-14) score was 22/52.

Laboratory investigations revealed elevated serum levels of creatine kinase, lactate dehydrogenase, aspartate aminotransferase, C-reactive protein, erythrocyte sedimentation rate, thyroid stimulating hormone, normal free triiodothyronine, and free thyroxine. Her Full blood count and renal function tests were normal, and Hepatitis B surface antigen (HBs Ag) and Hepatitis C virus antibody (HCV Ab) were both negative. 

Magnetic resonance imaging (MRI) of the proximal legs revealed increased signal intensity in muscular compartments seen as bright spots, signifying edema of the thigh muscles. Her X-rays of the limbs and echocardiogram were normal.

Based on these, she received the diagnosis of JDM with autoimmune thyroiditis.

The patient received intravenous methylprednisolone (30 mg/kg for three days) followed by oral prednisolone (60 mg/m2). She also received an immediate dose of intravenous cyclophosphamide (500 mg/m2), followed by weekly oral methotrexate (10 mg). Her other medications included oral folic acid, calcium carbonate, omeprazole, and topical mupirocin. She received daily physiotherapy.

Following treatment, her condition improved. Yet, the macules on the knee and ankle stiffness persisted.

She received a discharge after six weeks, with instructions regarding medication, physiotherapy, and follow-up.

At follow-up, on a maintenance dose of 10 mg methotrexate weekly and daily folic acid at 5 mg/day, she showed improvement in her muscle power, pain, and stiffness. Her tiptoe gait persisted. 

Mussa F, Nalitolela N, Fredrick F. An 8-year-old-girl with juvenile dermatomyositis and autoimmune thyroiditis in Tanzania: a case report. J Med Case Rep. 2021 Dec 27;15(1):632. doi: 10.1186/s13256-021-03222-5. PMID: 34955096; PMCID: PMC8711193.