Osteoporosis in a patient with recessive dystrophic epidermolysis bullosa

Correlates of low bone mass in children with generalized forms of epidermolysis bullosa

BACKGROUND

Epidermolysis bullosa (EB) is a family of rare, heterogeneous, genetic disorders characterized by fragility of the skin and mucous membranes. Reduced bone mass and fractures have been recognized as complications of generalized forms of EB.

OBJECTIVES

We sought to describe the range and to estimate the prevalence of low bone mass in children with generalized EB, and to identify correlates of low bone mass in this population.

METHODS

This was a prospective, observational study of 24 patients with generalized EB. Each patient completed a history, physical examination, laboratory studies, bone age, and x-rays of the lumbar spine. Those aged 6 years and older underwent dual energy x-ray absorptiometry scans of the lumbar spine. Primary outcomes were areal bone mineral density (aBMD) based on chronologic age, bone age, and adjusted for height Z-score. Descriptive statistics were used to summarize results, and linear regression was used to determine factors associated with low aBMD.

RESULTS

Mean lumbar spine aBMD Z-scores ± SD were: -2.6 ± 1.4 for chronologic age, -1.7 ± 1.3 for bone age, and -1.0 ± 1.2 after adjusting for height Z-score. aBMD Z-scores were less than or equal to -2 in 64% for chronologic age, 50% for bone age, and 28% after adjusting for height Z-score. aBMD correlated with height Z-score, weight Z-score, extensive blistering, immobility, albumin, hemoglobin, iron, erythrocyte sedimentation rate, and c-reactive protein values.

LIMITATIONS

Small sample size was a limitation.

CONCLUSIONS

Children with severe, generalized recessive dystrophic EB have low aBMD for age. Deficits in aBMD were reduced after adjusting for delayed skeletal maturation and small body size.

Severe osteoporosis treated with teriparatide in a patient affected by recessive epidermolysis bullosa dystrophica

In this work, we describe the clinical and instrumental results of our experience, the first reported in the literature, of the administration of teriparatide to treat severe osteoporosis secondary to epidermolysis bullosa. Already after 2 months of therapy, the patient, a 20-year-old affected by a recessive form of epidermolysis bullosa dystrophica, had less pain and a functional recovery resulting in an improved autonomy; a satisfactory increase in the densitometric values was documented.

Vitamin and trace metal levels in recessive dystrophic epidermolysis bullosa

BACKGROUND

In recessive dystrophic epidermolysis bullosa (RDEB), a good nutritional balance is necessary to obtain healing of the chronic wounds. However, involvement of the oral mucosa and oesophagus stenosis may be responsible for severe nutritional deficiencies.

OBJECTIVE

In order to propose an adapted nutritional management, we studied the vitamin and trace metal status of 14 RDEB patients.

METHODS

Height and weight were measured. Plasma levels of albumin, iron, ferritin, calcium, parathyroid hormone (PTH), folates, vitamins C, D, B12, A, E, B1, B6, PP and B2, zinc, selenium, carnitine and copper were measured.

RESULTS

Most patients had a significant growth retardation. We found iron, vitamin D, C, B6, PP, zinc and selenium deficiencies in 36-70% of the patients, without clinical expression, except in one case. Vitamin B1, 12, B2, A/RBP, E/lipids and carnitine were normal. The three patients with gastrostomy feeding had better growth but still a protein deficiency and sometimes vitamin C, B6, PP, zinc and carnitine deficiencies.

CONCLUSION

Vitamin and trace metal deficiencies are frequent in RDEB, even in patients receiving gastrostomy feeding, and often go unrecognized. Regular nutritional evaluation is necessary. Dietary advice and supplements should be given. Enteral feeding by gastrostomy should be discussed in early childhood.