麻豆传媒

"Medical Journeys" is a set of clinical resources reviewed by physicians, meant for the medical team as well as the patients they serve. Each episode of this journey through a disease state contains both a physician guide and a downloadable/printable patient resource. "Medical Journeys" chart a path each step of the way for physicians and patients and provide continual resources and support, as the caregiver team navigates the course of a disease.

This month: A noteworthy case study.

Why has this otherwise healthy 15-year-old young woman developed osteoporosis at the age of 15? That's the diagnostic challenge described by Karniza Khalid, MBBS, MMedSc, of the Ministry of Health Malaysia in Kuala Lumpur, and colleagues in a recent issue of .

The patient, who was referred from an orthopedic colleague, had suffered a T12 wedge fracture after a low impact trampoline injury. The medical team performed a detailed assessment, which revealed features of osteoporosis, with a dual x-ray absorptiometry scan showing that the patient's Z score was significantly reduced. The patient told clinicians that for the past 8 months, she had had unremitting low back pain and stiffness, and felt increasingly fatigued.

Clinicians ordered a thoracolumbar x-ray, which showed widespread biconcave and plate depression over the thoracic and lumbar vertebrae. There was also minor loss of body height at the T9 vertebra and some depression of the superior endplate of the T8 vertebra.

The patient's body mass index was 16.9, placing her in the third percentile, while her weight was just 36.2 kg (79.8 lbs), meaning that she was below the fourth percentile for her age and height. She also had mild kyphosis.

The case authors explained that imaging evidence of numerous wedge-shaped thoracolumbar compression fractures led them to suspect that endplate failure had played a role. Given the absence of previous long-term use of steroid therapy and other signs suggestive of a hematological disorder, the orthopedic team suspected that the patient had Scheuermann disease, and referred her to a dietitian.

Five months later, the patient returned to the hospital with ongoing lethargy and patches of ecchymoses over both knees, and she was readmitted for further assessment. She also had diffuse perifollicular hemorrhages and hyperkeratotic papules over both lower limbs and forearms, which she said had been stable for the past 2 years with no acute worsening.

Peripheral examination showed that her joints were neither swollen nor tender, and there was no evidence of palpable masses or lymphadenopathies. Other systemic findings were also unremarkable. The patient blood pressure and resting heart rate were normal for her age, the team said.

"Our first clinical impression at that point was autoimmune disorders or vasculitis," Khalid and co-authors wrote. Various lab tests, including assessment of serum electrolytes, trace minerals, and thyroid function, returned findings that were considered ambiguous.

The patient's renal function, liver function, coagulation profile, and levels of vitamin B12 and folate were within normal ranges, and she had "acceptable" levels of vitamin D and iron. "Her immunological screening with rheumatoid factor and anti-nuclear antibody came back negative," the case authors stated. She did, however, have a slightly elevated erythrocyte sedimentation rate of 42 mls/h (N: 0–20 mls/h) and her C-reactive protein was 6 mg/L (N < 5 mg/L).

The team took a detailed history of her dietary habits, which they felt suggested "anorexic behavior of restrictive type since the age of 10." In light of this, the team checked the patient's serum vitamin C, which was "undetectable" (N = 26–85 umol/L).

Her diet, clinicians then learned, was usually two slices of dry toast and plain pasta for breakfast, and chocolate rice cakes for lunch and tea. Notably lacking was any red meat, fish, chicken, green vegetables, or fruit. Otherwise, she had no history of prolonged diarrhea or vomiting, and there was no family history of gastrointestinal diseases. Results of screening for celiac disease were also negative.

Clinicians prescribed treatment with oral vitamin C supplement 500 mg daily, ferrous fumarate 1 capsule twice daily (100 mg elemental iron), and calcium carbonate 10 mmol every 6 hours. To rule out a psychogenic cause for her poor eating habits, the patient was referred for psychiatric assessment and psychological services, and she was also sent to a dietitian for a consultation and education on maintaining a healthy diet.

The team made a diagnosis of scurvy.

Discussion

Scurvy, a rare nutritional vitamin C deficiency, "is almost forgotten in developed economies," Khalid and co-authors explained. Thus, this rare instance of symptomatic scurvy in a Caucasian adolescent presented a noteworthy diagnostic challenge.

"This patient was initially referred due to concerns of anorexia nervosa or avoidant/restrictive food intake disorder," the team wrote. This resulted in a slightly extended pathway to diagnosis, including time required for routine tests of vitamin D and calcium levels.

Scurvy is diagnosed clinically, based on of "diffuse perifollicular purpura with corkscrew hair in the presence of low vitamin C level," Khalid and co-authors said. People with scurvy are typically older, and the disease may also be with conditions such as malabsorption, malnutrition, and alcoholism.

"Vitamin C deficiency also causes alteration in the structural collagen, contributes to defective osteoid matrix formation and leads to an increase in bone resorption," the case authors wrote. "The normocytic nonregenerative anemia associated with scurvy is , often coupled with iron, vitamin B9, and B12 deficiencies with evidence of systemic inflammation ...clinicians should be wary of the disease as it is still being sporadically reported."

Once other hematologic conditions have been ruled out, scurvy should be considered a possible diagnosis in patients with skin symptoms such as perifollicular purpura and/or bleeding tendencies, the team said. Scurvy is characterized by perifollicular hemorrhage – "a tell-tale sign of a severe vitamin C deficiency," which occurs when small blood vessels become fragile and rupture, leading to small areas of bleeding around the hair follicles.

The case authors said that while scurvy may present with "dramatic" symptoms, the condition is easily reversed when vitamin C levels are restored. The physiologic activity of vitamin C is wide-ranging, the authors explained, beginning with its "vital role in the maintenance of oxidation–reduction (redox) balance, tyrosine metabolism, and carnitine synthesis." In addition, severe vitamin C deficiency can interfere with treatment effectiveness in patients with chronic degenerative and autoimmune diseases, and malignancy.

About 80% of patients with scurvy develop musculoskeletal symptoms such as pain in the joints or muscles, as well as hemarthrosis or muscular hematomas. X-ray assessment may show "osteolysis, loss of joint space, osteopenia, or periosteal proliferation, with trabecular and cortical osteoporosis being a common observation," the group wrote. "This case highlights that vitamin C deficiency is still relevant in the modern era and raises the need to educate the primary care provider, who are often the first contact, for prompt diagnosis and treatment."

Read previous installments in this series:

Part 1: New Insights Into the Complex Biology of Osteoporosis

Part 2: The Latest on Osteoporosis Treatment and Diagnosis

Part 3: Osteoporotic Fragility Fractures

Part 4: Case Study: First-Time Mom's Severe Low Back Pain After Breastfeeding

Part 5: As Men Live Longer, Osteoporosis Looms Larger

Part 6: These Other Medical Conditions and Treatments Can Also Increase Osteoporosis Risk

Part 7: Talking to Patients About Osteoporosis