Microgeodic disease in an infant
- 1 General Paediatrics, The Royal Children's Hospital, Parkville, Victoria, Australia
- 2 Rheumatology, Monash Children's Hospital, Clayton, Victoria, Australia
- 3 Rheumatology, The Royal Children's Hospital Melbourne, Parkville, Victoria, Australia
- 4 Radiology Department, The Royal Children's Hospital, Parkville, Victoria, Australia
- Correspondence to Dr Katrina Frances Stranks; katrinastranks@gmail.com
Abstract
We describe an infant presenting with intermittent discolouration and swelling of her fingers and toes occurring with changes in ambient temperature. Extensive investigations revealed raised inflammatory markers as well as sclerotic lesions within the phalanges and diffuse marrow oedema. Infectious and inflammatory causes were considered and excluded based on the clinical presentation and investigation findings. The persistence of symptoms prompted further investigation with MRI. Correlation of the MRI findings with previous case reports resulted in a diagnosis of microgeodic disease—an uncommon, self-limiting condition thought to be due to cold-induced vasospasm leading to avascular necrosis of the bone.
Background
Microgeodic disease is an uncommon disorder that can produce discolouration and swelling of the hands and feet.1–3 It is often not considered and can be misdiagnosed due to its similarities with more benign differentials such as perniosis (chilblains) – where bony involvement is absent.4 5 If misdiagnosed, potential complications such as fractures are not recognised and the patient may be exposed to unnecessary or invasive investigations and ineffective therapies.1 3 Recognition of this condition and its pathogenesis will help to improve management of similar cases and avoid complications or unnecessary treatment.3 6 7
Case presentation
An infant presented to the emergency department of a hospital in metropolitan Melbourne, Victoria with a 2-day history of swelling and discolouration of the fingers of her right hand but sparing of the thumb (figures 1 and 2). This was associated with slight irritability and reduced feed volumes, but there were no recorded fevers. There was no history of preceding trauma, recent travel or unwell contacts. In the preceding month, she had a history of intermittent blue discolouration of both hands and feet, involving different fingers and toes, especially in the mornings. These episodes self-resolved and were labelled as likely Raynaud’s phenomenon by her general practitioner. She was otherwise a well child, with no significant medical or family history, and was fully immunised.
Right hand at presentation.
Generalised oedema and erythema of the right four fingers extending to the palm at presentation.
On examination, she was alert and interactive, and routine observations were within normal limits. There was generalised oedema and erythema of the right four fingers extending to the palm. The overlying skin was warm to touch, and there was limited range of movement in her fingers with no focal tenderness. The remainder of her physical examination was unremarkable.
She was commenced on intravenous flucloxacillin for suspected cellulitis and transferred to a tertiary children’s hospital for further investigation and management.
Investigations
Initial investigations revealed a mildly elevated C reactive protein of 22.5 mg/L and erythrocyte sedimentation rate of 22 mm/hour in the setting of a normal white cell count. In retrospect, these raised inflammatory markers were likely secondary to the patient concurrently having gastroenteritis. The patient’s haemoglobin was 105 g/L with a a mean cell volume (MCV) of 84 f/L, indicating a normocytic normochromic anaemia. A blood film showed no definitive sickle or boat shaped cells and haemoglobin electrophoresis, thalassaemia screen, antinuclear antibody, syphilis serology, Mantoux and antistreptolysin-O titre were all unremarkable.
X-ray of the right hand revealed a small sclerotic line at the mid fifth metacarpal shaft, suspicious of a fracture (figure 3).
X-ray of right hand at presentation demonstrating rarefaction and periosteal reaction in the third, fourth and fifth middle phalanges, distal fourth phalanx, proximal third and fifth phalanges. Associated cortical punched out metaphyseal lesions and swelling of the overlying soft tissues are evident.
During the admission, the patient developed swelling of the fingers of the left hand. Therefore, the left hand and both feet were also radiographed. These X-rays were remarkable for subtle lucent foci in the left distal phalanges of the second, fourth and fifth fingers as well as in left first metatarsal distal diaphysis.
An ultrasound of the hand subsequently showed an area along the proximal third and fifth phalanx, suggestive of periostitis with no distinct drainable collection, raising concerns about possible osteomyelitis (figures 4 and 5).
Ultrasound image showing hypoechoic thickened periosteum over the fifth proximal phalanx (PP).
Colour Doppler ultrasound image showing hyperaemia of the periosteum of the fifth proximal phalynx (PP).
A subsequent MRI of the right hand revealed diffuse marrow oedema with associated patchy enhancement involving the phalanges of all fingers (figure 6).
Coronal T2-weighted fat suppressed MRI of the right hand showing diffuse marrow oedema of the involved phalanges and intramedullary lytic areas with extensive surrounding soft-tissue inflammation.
Differential diagnosis
The differential diagnoses considered during the admission included: sickle cell dactylitis, chilblains, spondyloarthritis or infections including cellulitis, osteomyelitis, syphilis and tuberculous dactylitis. These conditions may present with peripheral swelling and discolouration; however, in this case investigation results were inconsistent with these diagnoses as documented above.
Treatment
Despite broadening of antibiotic cover (intravenous flucloxacillin and ceftriaxone) the hand swelling fluctuated in severity and progressed to involve the left second, fourth and fifth digits with no overall clinical improvement. The antibiotic regimen was rationalised to single agent intravenous cephazolin and she was transferred on day seven of admission to a paediatric tertiary centre for further investigation including MRI to exclude multifocal osteomyelitis, and seek specialty team opinions from rheumatology, infectious diseases and plastic surgery.
Outcome and follow-up
Following transfer, antibiotic therapy was downgraded to oral cephalexin based on the clinical impression that osteomyelitis was unlikely. Further history revealed possible exposure to low temperatures at home overnight with the child’s hands frequently uncovered during sleep in the period leading up to her presentation. Correlation of this history, typical MRI findings and review of published clinical case reports led to a diagnosis of microgeodic disease.
The family was educated on the importance of keeping the child warm and dry in order to prevent recurrence of symptoms and possible bony injury. Following discharge home, there was a complete clinical recovery and improvement in imaging findings with conservative management. This included regulating the temperature at home and increasing clothing layers both on the core and peripheries, such as wearing gloves when outside. Follow-up X-ray at 2 months showed bony expansion and resolution of the cortical irregularities (figure 7).
X-ray of right hand at resolution.
Discussion
The term microgeodic disease was first described by French radiologist Maroteaux in 1970 who discovered small punched out lacunar-like osteolytic lesions in the phalanges of five infants on X-ray.1 2 Since first reported, it has been well described but rarely in infants, with an average age at diagnosis of 7 years.1 To our knowledge, the case reports that have described microgeodic disease in infants and children, have been in patients without a concurrent infection.2 5 8 In this case, raised inflammatory markers were initially misleading due to concurrent infection; however, this demonstrates that an awareness and index of suspicion for microgeodic disease is required to establish the diagnosis.
There have been five case reports of microgeodic disease described in the adult population.9 These cases, such as a recent case presented by Ellatif et al, frequently describe phalangeal swelling and discolouration associated with pain as the presenting complaints. This differs from the majority of case reports in children and infants, who are often asymptomatic or have mild pain and tenderness on examination.5 6 8
Pathognomonic imaging findings, correlated with the clinical manifestations, are widely accepted as the cornerstone for diagnosis of microgeodic disease.6 The classic X-ray finding of multiple, small, well-defined osteolytic foci in the medulla and cortex of the affected phalanges was described by Maroteaux as ‘microgeodes’—the origin for the name microgeodic disease.1 2 5 On some occasions, metaphyseal transverse lucent bands have been also reported, along with periostitis.5 In this case, periostitis was appreciable on ultrasound which is uncommon. Resolution of X-ray findings are usually within 6 months with conservative management.10
A lack of any X-ray changes, despite clinical manifestations correlating with pathognomonic MRI findings, is not unusual as described in case reports by Lee et al.3 The value of MRI in this setting is the increased sensitivity for diagnosing radiographically occult disease.8 11 The characteristic finding on MRI is diffuse signal change in the affected phalanges, specifically T1-hypointense signal and short-tau inversion recovery(STIR)-hyperintense signal, representing bone marrow oedema.7 11 Associated soft-tissue swelling, such as in this case, is often seen on X-ray and MRI; however, joint effusions are unusual.5 The MRI findings in this case were typical of microgeodic disease, with diffuse marrow oedema of the involved phalanges and intramedullary lytic areas. The presence of these classic findings, in particular osteolytic lesions, in the context of the above pathology results made other diagnoses less likely and helped to confirm microgeodic disease.
A large case series reported by Yang et al postulated that microgeodic disease may represent bone absorption and destruction in response to exaggerated peripheral circulatory changes following chilblains, mainly occurring in bone growth spurts.5 Similarly, Radhakrishnan et al suggested that microgeodic disease could be caused by a final common pathway of reversible bone death due to several different mechanisms including: the cutaneous tissue injury caused by reflex vasodilatation and vasospasm in chilblains; tissue death in frostbite or vasospasm in Raynaud’s phenomenon.7 It appears that microgeodic disease may represent the extreme end of a spectrum of peripheral circulatory disorders induced by cold temperatures.9 12 In order to exclude alternative diagnoses, some patients have been investigated extensively with nuclear imaging and even biopsy, which could be avoided if the spectrum of Raynaud’s to microgeodic disease was better recognised by the clinician.6 Similarly, treatment with antibiotics, anti-inflammatories and other unnecessary pharmacotherapies can be avoided with appropriate diagnosis. Once recognised, the majority of cases will heal spontaneously without residual deformity, however, rare complications include pathological fracture and subsequent malunion.11 13 14
Treatment for microgeodic disease is largely supportive, aimed at keeping the patient warm and dry.1 13 As in our case, this involves avoiding exposure to the cold by wearing layered clothing and keeping peripheries covered. It has been proposed that a splint may protect severely affected digits from potential complications such as stress fractures or physical damage to the growth plate and avoid digital shortening.10 14
The disorder is rarely described in temperate climates which raises the possibility that duration of exposure may be a factor in its development, rather than simply extremes of temperature. This was indeed the case in this patient, who was noted to spend hours overnight with her hands above her head as her favoured sleeping position. Other individual factors, including genetic factors, may also be contributors.
Learning points
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Microgeodic disease is an under-recognised cause of discolouration and swelling of phalanges in infants.
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While the pathogenesis of this disease is unknown, it is thought to be a transient disturbance of the peripheral circulation caused by cold temperatures. We propose a spectrum of disease with Raynaud’s and chilblains at the milder end, and microgeodic disease at the more severe end when bony changes are evident with classically described features on MRI.
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The typical imaging findings, best demonstrated on MRI, confirm the diagnosis without the need for biopsy or surgical treatment.
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While the disease course is mostly benign, complications such as fracture and digit shortening can occur.
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Consideration of this diagnosis is crucial to avoid unnecessary invasive diagnostic procedures and should prompt a conservative management approach.
Ethics statements
Patient consent for publication
Footnotes
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Contributors KFS cared for the patient, collected patient information and coauthored the report. GT cared for the patient, served as scientific advisor, critically reviewed and coauthored the report. NL served as scientific advisor, critically reviewed and coauthored the report. DB cared for the patient, collected patient information, served as scientific advisor, critically reviewed and coauthored the report.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
References
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