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 Table of Contents  
Year : 2022  |  Volume : 2  |  Issue : 2  |  Page : 79-83

Atypical kawasaki disease with polymyositis and panniculitis: Case report and review of literature

1 Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India
2 Department of Cardiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry, India

Date of Submission01-Jan-2022
Date of Decision07-Apr-2022
Date of Acceptance26-Apr-2022
Date of Web Publication30-May-2022

Correspondence Address:
Dr. Dhandapany Gunasekaran
Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry - 605 006
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ipcares.ipcares_1_22

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Background: Kawasaki disease (KD) is a medium-vessel vasculitis that commonly affects young children. Many atypical presentations that differ from the classical phenotype have been described. Clinical Description: A 3-year-old boy presented with acute onset refusal to walk due to severe pain in both lower limbs for 8 days. This was accompanied by fever for 7 days. Significant findings included diffuse tenderness of bilateral thighs and leg muscles, probable normal joints, and absence of rashes, edema, significant lymphadenopathy, organomegaly, or paralysis. He had a hemoglobin of 10.6 g/dL, neutrophilic leukocytosis, and normal platelet count (384 × 109/L). He was started on intravenous cloxacillin, assuming polymyositis or acute osteomyelitis. Radiographs, ultrasonography, and bone scan of the lower limbs revealed normal bones and joints. However, magnetic resonance imaging detected patchy hyperintensities in multiple muscles, though muscle-specific enzyme levels were normal. The fever and pain persisted and investigations for other differentials (including classical KD) were inconclusive. At the end of 2nd week of illness, atypical KD was suspected, when he developed periungual skin peeling with increasing erythrocyte sedimentation rate and platelet counts. Management: The diagnosis was confirmed by echocardiogram proven left main coronary artery dilatation. He was started on intravenous immunoglobulin. Since fever persisted, a second dose was administered, following which defervescence occurred and his symptoms subsided. Conclusions: Atypical KD should be considered in a fever of unknown origin when diagnostic criteria of classical KD are not satisfied. Polymyositis and panniculitis are uncommon atypical manifestations.

Keywords: Atypical Kawasaki disease, intravenous immunoglobulin resistance, polymyositis; subcutaneous nodules

How to cite this article:
Rajasegar R, Sugumar K, Chandrasekaran V, Gunasekaran D, Anantharaj A. Atypical kawasaki disease with polymyositis and panniculitis: Case report and review of literature. Indian Pediatr Case Rep 2022;2:79-83

How to cite this URL:
Rajasegar R, Sugumar K, Chandrasekaran V, Gunasekaran D, Anantharaj A. Atypical kawasaki disease with polymyositis and panniculitis: Case report and review of literature. Indian Pediatr Case Rep [serial online] 2022 [cited 2023 Jun 3];2:79-83. Available from: http://www.ipcares.org/text.asp?2022/2/2/79/346244

Kawasaki disease (KD) is a medium-vessel vasculitis that commonly affects children <5 years of age.[1] The clinical spectrum of KD varies from complete KD (the typical presentation) to incomplete and atypical forms, which often pose as a diagnostic challenge. The typical manifestations of complete KD in the 1st week of illness include fever for at least 5 days, bilateral nonpurulent conjunctivitis, cervical lymph node enlargement, redness of the lips and tongue, erythema or edema of the palms and soles, and a polymorphous rash.[1] Children who present with fever of the same duration but with fewer physical criteria are considered to have incomplete KD.[2] Although the terms incomplete and atypical KD are used interchangeably, atypical KD refers to the presence of manifestations that are not commonly seen in the complete or incomplete phenotypes, i.e., renal impairment, facial nerve palsy, gastrointestinal manifestations, and testicular swelling.[2]

We report a child who presented with pain in both lower limbs and fever, whose initial provisional diagnosis was myositis/osteomyelitis, but further workup established the diagnosis of atypical KD. A literature search revealed very few cases of atypical KD presenting with polymyositis.[3],[4],[5] This report serves a dual purpose, adding evidence to expand the clinical repertoire, as well as providing a brief review of the heterogeneous presentations of atypical KD.

  Clinical Description Top

A 3-year-old boy was brought to our hospital with pain in both lower limbs for 8 days and fever for 7 days. Apparently healthy before presentation, he went to bed symptom-free, and awoke in the morning with diffuse pain that was restricted to only both lower limbs. It was severe enough to result in him refusing to walk, though there was no loss of movement. The next day he developed fever, moderate in degree, and not associated with chills or rigors. There was no history of local swelling in either lower limb, or warmth, redness, or stiffness of his ankles, knees, or hips. There was no history of any rash, cough, coryza, sore throat, breathlessness, or palpitations. There was no history of preceding trauma or bleeding from any site, progressive pallor, loss of weight or appetite. Bowel and bladder habits remained unchanged, though he had difficulties in squatting. His sensorium was normal, though he was irritable due to the pain. There was no history of similar complaints in the past or of history suggestive of previous cardiac or gastrointestinal involvement, or exanthematous illness. He was the second born to nonconsanguineous parents, and the family history was not significant. He had a smooth perinatal transition, was developmentally normal, vaccinated as per the national immunization schedule and was receiving an appropriate diet.

At the time of admission, he was febrile (38.5°C), with tachycardia (pulse rate of 136/min), and normal respiratory rate (28/min), blood pressure (between 50th and 90th centiles), and capillary refill time (<2 s). Anthropometry was appropriate for age with weight for age, height for age, and weight for height between 0 and-1 Z scores. Pallor, icterus, clubbing, pedal edema, and significant lymphadenopathy were absent. There were no rashes, petechiae, or ecchymosis; mucosa of the oral cavity, lips, and tongue was normal. The Bacille Calmette-Guérin scar appeared normal. Musculoskeletal examination revealed diffuse tenderness over bilateral extensor aspects of the thighs and legs, without erythema, swelling, or increased temperature of the joints. Localized joint tenderness or restricted range of motion of any joint was difficult to ascertain as the child cried whenever any part of the lower limb was touched. Local examination of the spine was normal. The motor component of the central nervous system examination (CNS) of the lower limbs revealed normal bulk, but the gait, power, tone, and deep tendon reflexes could not be precisely assessed due to the marked pain and tenderness. The remaining CNS, cardiovascular, respiratory, and abdominal examinations were noncontributory.

Since the clinical phenotype comprised acute-onset musculoskeletal involvement, of bilateral lower limbs with fever, the possibility of an infectious, inflammatory, or autoimmune etiopathogenesis was considered. [Table 1] lists the differential diagnoses that were included based on the clinical phenotype at admission: acute polymyositis, acute osteomyelitis, septicemia, septic arthritis/reactive arthritis, and acute rheumatic fever (ARF).
Table 1: Differential diagnoses considered based on the timeline of illness

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  Management and Outcome Top

Preliminary investigations revealed an elevated erythrocyte sedimentation rate (ESR) of 105 mm at 1-h, neutrophilic leukocytosis with total leukocyte count (TLC) 25 × 109/L, a differential count of 75% neutrophils (N), 15% lymphocytes (L), 6% eosinophils (E), and 4% monocytes (M), mild anemia (hemoglobin 10.6 g/dL), normal platelet count (384 × 109/L), and a peripheral smear displaying normocytic normochromic red blood cells with absence of atypical or malignant cells. Since this favored the acute infectious differential diagnoses of acute polymyositis or acute osteomyelitis, he was empirically started on intravenous cloxacillin and oral ibuprofen, pending further investigation reports. The roentgenograms of femur, tibia, and fibula were normal (though done on day 9 of illness). The absence of joint effusion on ultrasonography of the hip, knee, and ankles excluded any form of arthritis. Magnetic resonance imaging (MRI) of the lower limbs showed diffuse patchy areas of hyperintensities in all the muscles of the thigh, involving all the compartments [Figure 1]. However, the levels of serum creatine kinase (CK) and lactate dehydrogenase (LDH) were normal; 35U/L (normal range: 5–130 U/L) and 145 IU/L (normal range: 150–500 IU/L), respectively. Since radiographs cannot conclusively exclude acute osteomyelitis when performed early, a Technetium-99 bone scan was undertaken and proved to be normal. Liver and kidney function tests showed no evidence of organ dysfunction. Two blood cultures sent within a 24-h span were sterile. The diagnostic criteria of classical KD and Jones criteria for ARF were applied but were not satisfied. Since the acute infectious etiologies were ruled out, and the symptoms were still persisting, we started considering other diagnoses that would match the evolving clinical phenotype [Table 1]. A normal bone marrow examination ruled out hematoreticular malignancies and other infiltrative disorders. A negative serum anti-nuclear antibody test and the absence of uveitis excluded systemic-onset juvenile idiopathic arthritis (SOJIA). Although less likely, we even ruled out the possibility of an acute pain crisis associated with sickle cell anemia by a negative sickling test.
Figure 1: MRI of lower limbs (a) and (b) showing diffuse patchy areas of hyperintensities noted in all the muscles of thigh involving all compartments (white arrow). Few patchy hyperintensities also noted in the subcutaneous tissues in posterior aspect of right thigh and medial aspect of left thigh (white doted arrow). MRI: Magnetic resonance imaging

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By the end of the 2nd week, the child developed periungual desquamation in the child's toes, though redness of lips, strawberry tongue, conjunctival congestion, edema of the dorsal aspect of hands and feet, rash, and significant lymphadenopathy were absent. Other new findings noted were painless, subcutaneous nodules on the extensor aspect of the left forearm and the shin of the right leg, the biopsy of which revealed panniculitis. Repeat laboratory parameters revealed increasing leukocytosis (TLC 35.25 × 109/L with 73% N, 18% L, 5% E, and 4% M), thrombocytosis (690 × 109/L), and further rise in ESR (120 mm at 1-h). At this point of time, the possibility of atypical KD and multisystem inflammatory syndrome in children were considered [Table 1]. Reverse transcription polymerase chain reaction, as well as antibodies for coronavirus disease- 2019 were negative. An echocardiogram revealed a thin rim of pericardial effusion and dilatation of the left main coronary artery (LCA) with 2.55 Z (normal cut off <2 Z score) as apparent in [Figure 2]a and [Figure 2]b, thereby satisfying the diagnostic criteria for atypical KD [Table 1].
Figure 2: (a and b) Parasternal short axis view showing dilated LCA with a focal aneurysm measuring 6.61 mm in color compare mode. (b) Parasternal short axis view showing dilated LCA (4.76 mm) bifurcating into left anterior descending (2.31 mm) and left circumflex artery (2.13 mm). LCA: Left main coronary artery

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Hence, the final diagnosis of atypical KD was established on the 13th day of illness. As per standard protocol, he was started on intravenous immunoglobulin (IVIg) in a single dose of 2 g/kg with aspirin (75 mg/kg/day). Since there was no defervescence within 72 h of the first dose, a second dose of IVIg was tried. Following this, the fever subsided, the limb pain gradually resolved over the next 4 days, and by the 5th day the child had become ambulatory. He was discharged on low-dose aspirin (5 mg/kg/day). On follow-up, 4 weeks later, he remained symptomless. However, since repeat echocardiography showed persistent dilatation of the LCA, clopidogrel (1 mg/kg/day) was added to the low-dose aspirin.

  Discussion Top

KD is an important cause for acquired heart disease in children,[6] presumed to be triggered by a respiratory illness in genetically predisposed individuals. It is the most common vasculitis in children, with a predilection for involving the coronary arteries. Complications include coronary artery dilation and aneurysm in 25% of untreated patients and 4% with treatment.[5] The diagnosis of KD is established by a set of clinical criteria, which many infants and young children may not satisfy, as in this case. It is important to recognize that the terms “incomplete” and “atypical” KD does not imply that the disease is milder than classical KD. On the contrary, these children can often have devastating coronary sequelae as the diagnosis and treatment usually get delayed. We established the diagnosis and initiated specific therapy 5 days after hospital admission, which was the 13th day of illness. Musculoskeletal involvement as the primary manifestation of KD is uncommon, and rarely reported. In this child, the diagnostic dilemma arose once we excluded the common acute infectious causes. Although it is known that the onset of systemic symptoms can precede arthritis in SOJIA, nonetheless, the diagnosis cannot be made without evidence of joint involvement. Both KD and SOJIA are inflammatory disorders that share common triggering agents and immunologic pathways. Interestingly, coronary dilation has also been reported in SOJIA.

A literature search identified cases with a similar presentation. Singh et al. reported a 10-year-old boy suspected to have acute osteomyelitis, who was later diagnosed with KD.[7] KD presenting with myositis has been reported as early as 1980.[8] This child had clinical polymyositis, MRI evidence of extensive muscle involvement, but the typical elevation of muscle-specific enzymes CK, LDH, and SGOT that is commonly seen in infectious myositis, was absent. This may possibly be explained by the fact that the levels were done in the premuscle necrosis stage, and the timely administration of IVIg prevented it from progressing to the necrotic stage when the enzyme elevation is seen. A summary of the few other cases of KD presenting with myositis that we found on a literature search is given in [Table 2]. The common manifestations were fever and muscle pain. The other associated complaints were diverse, such as orbital cellulitis,[9] respiratory paralysis and dysphagia,[4],[5] and erythema nodosum in a 3-year-old girl with KD[10] (as in this case). The initial diagnoses considered by the treating physicians before establishing a diagnosis of KD included infectious mononucleosis, viral polymyositis, adverse drug reaction, and juvenile dermatomyositis.[11]
Table 2: Comparison of case reports of Kawasaki disease with myositis

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About 10%–20% of KD may not respond to the first dose of IVIg (IVIg resistance) and require a second dose, like in our child. It is likely that host genetic factors, such as polymorphisms in the Fc gamma receptors, play a role in both the response and resistance to IVIg.[12] It has been observed that patients who are initially IVIg resistant are at increased risk of developing severe coronary artery abnormalities. Resistance to the first dose of IVIg was also reported in a few cases of KD with myositis.[3] These children were noted to have persistent coronary dilatation on follow-up, as in this case.

Our case deserves special mention for two reasons: first, for the atypical presentation with polymyositis and cutaneous vasculitis; and second, the presence of IVIg resistance with persistent coronary dilatation. Atypical KD can closely mimic many diseases, thereby posing diagnostic dilemma even to the most astute clinicians. Thus, a clinician should keep a high index of suspicion of atypical KD in the setting of persistent fever, elevated inflammatory markers, and absence of any other plausible explanation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the parents have given their consent for the images and other clinical information to be reported in the journal. The parents understand that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


  References Top

McCrindle BW, Rowley AH, Newburger JW, et al. Diagnosis, treatment, and long-term management of Kawasaki disease: A scientific statement for health professionals from the American heart association. Circulation 2017;135:e927-99.  Back to cited text no. 1
Newburger JW, Takahashi M, Gerber MA, et al. Diagnosis, treatment, and long-term management of Kawasaki disease: A statement for health professionals from the committee on rheumatic fever, endocarditis, and Kawasaki disease, council on cardiovascular disease in the young, American heart association. Pediatrics 2004;114:1708-33.  Back to cited text no. 2
Vigil-Vázquez S, Butragueño-Laiseca L, López-González J., A case of Kawasaki disease presenting as severe myositis. Indian J Pediatr 2019;86:1066-7.  Back to cited text no. 3
Gama C, Breeden K, Miller R. Myositis in Kawasaki disease. Pediatr Neurol 1990;6:135-6.  Back to cited text no. 4
Koutras A. Myositis with Kawasaki's disease. Arch Pediatr Adoles Med 1982;136:78.  Back to cited text no. 5
Singh S, Kawasaki T. Kawasaki disease in India, lessons learnt over the last 20 years. Indian Pediatr 2016;53:119-24.  Back to cited text no. 6
Singh SP, Ansari NH, Tanwar YS., Osteomyelitis in Kawasaki disease. Indian J Pediatr 2014;81:1384-6.  Back to cited text no. 7
Koutras AK. Myositis with mucocutaneous lymph-node syndrome. N Y State J Med 1980;80:1138-9.  Back to cited text no. 8
Lin H, Burton EM, Felz MW. Orbital myositis due to Kawasaki's disease. Pediatr Radiol 1999;29:634-6.  Back to cited text no. 9
Okada S, Ishikawa Y, Shimomura M, et al. Erythema nodosum masking Kawasaki disease with an initial manifestation of skin lesions. Yonsei Med J 2019;60:312-4.  Back to cited text no. 10
Anjani G, Johnson N, Navid A, et al. Kawasaki disease malingering as juvenile dermatomyositis: Case-based review: Myositis in Kawasaki disease. Rheumatol Int 2022;42:913-9.  Back to cited text no. 11
Tremoulet AH, Best BM, Song S, et al. Resistance to intravenous immunoglobulin in children with Kawasaki disease. J Pediatr 2008;153:117-21.  Back to cited text no. 12
Lee EY, Oh JY, Chong CY, et al. A case of atypical Kawasaki disease with myositis. Glob Pediatr Health 2015;2:1-6.  Back to cited text no. 13
Sugie H, Sugie Y, Ichimura M, et al. A case of polymyositis associated with Kawasaki disease. Brain Dev 1985;7:513-5.  Back to cited text no. 14
Agarwal S, Gupta A, Suri D, et al. Proximal muscle weakness in a child with Kawasaki disease. Indian J Pediatr 2015;82:866.  Back to cited text no. 15


  [Figure 1], [Figure 2]

  [Table 1], [Table 2]


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