Rare disease

CASE REPORT

Juvenile dermatomyositis in a Nigerian girl Olufemi Adelowo,1 Madu Nwankwo,2 Hakeem Olaosebikan1 1

Rheumatology Unit, Department of Medicine, Lagos State University Teaching Hospital, Lagos, Nigeria 2 Department of Medicine, Nnamdi Azikiwe University Teaching Hospital, Nnewi, Anambra, Nigeria Correspondence to Professor Olufemi Adelowo, [email protected] Accepted 9 March 2014

SUMMARY Juvenile dermatomyositis is an autoimmune connective tissue disease occurring in children less than 16 years old. It is part of a heterogeneous group of muscle diseases called idiopathic Iiflammatory myopathies. It had previously been reported in black Africans resident in UK. However, there is no documented case reported from Africa. The index sign of heliotrope rashes is often difficult to visualise in the black skin. An 11-year-old Nigerian girl presenting with clinical, laboratory and histopathological features of juvenile dermatomyositis is presented here. It is hoped that this case will heighten the index of suspicion of this condition among medical practitioners in Africa.

BACKGROUND Juvenile dermatomyositis ( JDM) is a rare multisystemic autoimmune disease of uncertain origin that results in chronic inflammation of striated, smooth muscles and skin in children less than 16 years of age.1 A few cases of this rare disorder have been reported among Africans outside the continent in a recent registry of cases of juvenile dermatomyositis seen in UK,2 but none has been reported among Black Africans resident in the continent. The hallmark of this disorder is the skin lesion which may be particularly difficult to recognise in black African skin.3 This case report is that of a Nigerian child who presented with clinical features of juvenile dermatomyositis and was subsequently investigated and managed.

CASE PRESENTATION

To cite: Adelowo O, Nwankwo M, Olaosebikan H. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013202132

An 11-year-old girl, Nigerian pupil, who presented to the Paediatric Clinic of the Lagos State University Teaching Hospital, Ikeja, Nigeria with a 3-month history of insidious onset of muscle weakness and pain principally affecting the proximal muscles of both arms and legs. This limited her from performing such diverse activities as getting up from a chair, climbing staircase upstairs, combing her hair and she is barely able to feed herself. There was associated fever, dysphagia, dysphonia, periorbital rash and swelling noticed by the mother. There was no joint pain, joint stiffness, oral sores, hair loss or thickening of the skin. Other medical history was, however, unremarkable. Physical examination showed an ill looking, febrile child with a temperature of 40.1°C with associated conjunctiva pallor and few palpable nodes in the neck. There was a heliotrope rash above both upper eyelids (figure 1). Musculoskeletal examination revealed minimal tenderness of the thigh and proximal arm muscles with marked difficulty in raising her arms above the

Adelowo O, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202132

Figure 1 Heliotrope rash in an 11-year-old Nigerian girl with dermatomyositis.

head. Muscle power in the proximal muscles was of grade 2–3 while the distal muscles had normal muscle power. There was no joint tenderness. All other systems were essentially normal. Laboratory investigations showed elevation of muscle enzymes: CK 3069 μ/L (26–140), myoglobin 314 ng/mL, aldolase 19 iu/L (1.5–8.1), alanine aminotransferase 50 μ/L (10–40), aspartate aminotransferase 184 μ/L (10–42), lactate dehydrogenase 783 μ/L (120–230), erythrocyte sedimentation rate (ESR) 60 mm/h (0–20), C reactive protein 110 mg/L (0–10) and serum ferritin 2057 μg/L (200–300). Serology for anti-Jo-I, antinuclear antibody and rheumatoid factor were all negative. Serology for HIV was negative while the tuberculin skin test was also negative. The chest radiograph was reported as normal. Electromyography (EMG) revealed myopathy without neuropathic changes. Nerve conduction study was however normal. Muscle biopsy revealed diffuse myositis with mononuclear infiltrates. The diagnosis of definite juvenile dermatomyositis was made based on the Bohan and Peter diagnostic criteria4 namely insidious onset of symmetrical proximal muscle weakness, heliotrope rash, raised muscle enzymes, myopathic EMG abnormalities and muscle biopsy showing histological features of myositis. 1

Rare disease Treatment was initiated with pulse intravenous methylprednisolone 0.5 mg/kg daily for 3 days followed by oral prednisone 30 mg daily in divided doses and calcium supplements. Physiotherapy was also initiated. There was resolution of fever and muscle pain within few days with gradual improvement in muscle strength within the next few weeks. Patient continues to feel well and she is presently on prednisolone tablets 20 mg daily while she continues physiotherapy.

INVESTIGATIONS ▸ ▸ ▸ ▸ ▸ ▸ ▸ ▸ ▸

Haematocrit White cell count ESR Liver enzymes Muscle enzymes Serology Chest radiograph EMG Muscle biopsy

DIFFERENTIAL DIAGNOSIS ▸ Systemic lupus erythematosus ▸ Muscle dystrophy

TREATMENT ▸ Corticosteroids ▸ Azathioprine ▸ Physiotherapy

OUTCOME AND FOLLOW-UP The patient got better and was discharged. She is still being followed up.

DISCUSSION Unverritcht had in 1887 previously clarified the muscular and cutaneous manifestation of dermatomyositis as a form of idiopathic inflammatory myopathy. Other forms include polymyositis and inclusion body myositis. However, there is an over-representation of juvenile dermatomyositis compared with adults. The diagnosis is usually made using the Bohan and Peter criteria developed in 1975. This is normally used in adults; however, this has been adapted for children as well. JDM is rarely reported in Black Africans. Probably the largest series was from the JDM registry report in the UK.2 A total of 258 cases of definite or probable juvenile dermatomyositis or juvenile polymyositis were recorded over a 10-year period in a multicentre study. Of this number, Caucasians accounted for 207 cases (80.2%) while Black Africans accounted for only seven cases (2.7%), among other ethnic groups. Out of the total number of cases seen, 42% had muscle biopsy while only 21 children had EMG studies. Diagnosis of juvenile dermatomyositis was made in the patient based on the presence of skin manifestation (heliotrope rash) and four other criteria namely proximal muscle weakness, raised muscle enzymes, myopathic EMG changes and diffuse mononuclear infiltrates on histopathology. Heliotrope rash and other skin signs such as Gottron’s sign, shawl and Holster’s signs are usually erythematous in Caucasian but violaceous or hyperpigmented in African skin and this may therefore make it less distinct.3 These signs are usually also influenced by the presence of antisynthetase antibodies, which are uncommon in

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children5 and may therefore explain why these signs were not florid in our patient. Dermatomyositis differs from polymyositis not only by the presence of skin manifestation but also by clinical presentation and biopsy findings.1 The presence of extra muscular features such as fever, dysphagia and dysphonia suggest more of dermatomyositis. The presentation of juvenile dermatomyositis differs from that of adult. Some important differences include the presence of fever, prominent muscle pains, more rapid onset and good response to treatment. It also differs in the increased incidence of overlap with other connective tissue diseases as well as presence of calcinosis.5 6 Our patient presented with fever, muscle pain, but did not have features of other connective tissue disease. Anti-Jo-1 was also negative. Calcinosis and metabolic abnormalities such as insulin resistance were not present in our patient possibly because of the short duration of the illness, while such are usually late sequelae of the disease. The patient was managed with corticosteroids and immunosuppressive drugs with resultant improvement of the condition. Although no established protocols exist at present for the management of juvenile dermatomyositis, evidence suggests that early aggressive management improves outcome whereas a longer duration of untreated disease is associated with a longer time to reach remission and higher rates of complications.7 Improving both longterm and short-term outcomes requires early recognition, prompt referral to specialist care and appropriate treatment of patients with JDM and other forms of idiopathic inflammatory myositis.5 6 This case report is presented to increase the awareness of this condition in black African children who present with manifestations of proximal muscle weakness. Acknowledgements The authors thank Clina Lancet Laboratories for the biochemical and serology reports and Professor Yomi Ogun, Consultant Neurologist, for the Electromyography (EMG) studies. Contributors OA made the diagnosis as the consultant rheumatologist and also charted out the management. MN, rheumatology resident, effected the diagnostic investigations and collated the results. HO (rheumatology resident) and MN searched the literature and wrote the first draft. Competing interests None. Patient consent Obtained. Provenance and peer review Not commissioned; externally peer reviewed.

REFERENCES 1 2

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Rider LG, Lindsley CB, Cassidy JT. Juvenile dermatomyositis, Textbook of paediatric rheum, 6th edn. Saunders, 2011: 375–414. Martin N, Krol P, Smith S, et al.; Juvenile Dermatomyositis Research Group. A national registry for juvenile dermatomyositis and other paediatric idiopathic inflammatory myopathies: 10 years experience: the juvenile Dermatomyositis National (UK and Ireland) cohort biomarker study and repository for idiopathic inflammatory myopathies. Rheumatology 2011;50:137–45. Dugan EN, Huber MA, Miller FW, et al. International myositis assessment and clinical studies group photoessay of the cutaneous manifestations of the idiopathic inflammatory myopathies. Dermatol Online J 2009;15:1. Bohan A, Peter JB. Polymyositis and dermatomyositis N Engl J Med 1975;292:344–7. Stringer E, Singh-Grewal D, Feldman BM. Predicting the course of juvenile dermatomyositis, significance of early and laboratory features. Arthritis Rheum 2008;58:3885–92. Rider LG, Lachenbruch PA, Monroe JB, et al. Damage extent and predictors in adult and juvenile dermatomyositis and polymyositis as determined with the myositis damage index. Arthritis Rheum 2009;60:3425–35. Kim S, El–Hallak M, Dedeoglu F, et al. Complete and sustained remission of juvenile dermatomyositis resulting from aggressive treatment. Arthritis Rheum 2009;60:1825–30.

Adelowo O, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202132

Rare disease

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Adelowo O, et al. BMJ Case Rep 2014. doi:10.1136/bcr-2013-202132

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Juvenile dermatomyositis in a Nigerian girl.

Juvenile dermatomyositis is an autoimmune connective tissue disease occurring in children less than 16 years old. It is part of a heterogeneous group ...
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