Acral ulcerations and osteolysis, a severe form of the carpal tunnel syndrome

Lost bones: differential diagnosis of acro-osteolysis seen by the pediatric rheumatologist

INTRODUCTION

Acro-osteolysis is a radiographic finding which refers to bone resorption of the distal phalanges. Acro-osteolysis is associated with various conditions and its presence should prompt the clinician to search for the underlying etiology. The aim of this review is to discuss disorders with which acro-osteolysis is associated and their distinguishing features, with a focus on the pediatric population.

METHODS

A targeted literature review was performed using the term "acro-osteolysis" in combination with other key terms. The primary search results were supplemented using reference citations. Articles published prior to the year 2000 were included if they described additional associations not encountered in the more recent literature.

RESULTS

Genetic disorders (particularly primary hypertrophic osteoarthropathy and skeletal dysplasias) and rheumatic diseases (particularly psoriatic arthritis and systemic sclerosis) are the most frequently encountered conditions associated with acro-osteolysis in children. Hyperparathyroidism, neuropathy, local trauma and thermal injury, and spinal dysraphism should also be included in the differential diagnosis.

CONCLUSION

Although acro-osteolysis is uncommon, its presence should prompt the clinician to consider a differential diagnosis based on clinical and radiographic features.

Carpal tunnel syndrome and associated nail changes: Review and examples from the author's practice

Carpal tunnel syndrome (CTS) is commonly seen by general practitioners and often presents with neurologic symptoms of nocturnal pain and paresthesia along the median nerve distribution. Approximately 20% of patients also present with cutaneous findings (ulcerations, blistering, sclerodactyly, nail dystrophy) characterizing a severe form called necrotic CTS. Necrotic CTS can also be associated with bone changes (acro-osteolysis). In the author's practice, combined nail and skin findings are not an uncommon presentation of CTS, although this form remains overlooked and underreported in the dermatological textbooks and studies. This manuscript aims to review the literature on CTS cases, with a specific focus on using associated nail findings as diagnostic clues. The literature review along with a few additional recent cases from the author's practice demonstrate that CTS is frequently accompanied by a variety of nail changes including koilonychia, longitudinal fissuring, Beau's lines, onychomadesis, melanonychia, nail thickening, hyperkeratosis, and ischemic ulcerations with paronychia. Furthermore, when these changes are limited to the second and third fingernails, they should prompt the diagnosis of CTS. Once suspected, diagnostic evaluation is not difficult and surgical management can resolve cutaneous findings and prevent irreversible changes such as acro-osteolysis.

Association of Acroosteolysis With Enhanced Osteoclastogenesis and Higher Blood Levels of Vascular Endothelial Growth Factor in Systemic Sclerosis

OBJECTIVE

Bone resorption of distal phalanges, or acroosteolysis (AO), can develop in patients with systemic sclerosis (SSc), causing pain and functional limitation. This study was undertaken to investigate whether AO may be associated with abnormal osteoclastogenesis in SSc patients and whether hypoxia may be involved in this process.

METHODS

Peripheral blood mononuclear cells (PBMCs) obtained from 26 SSc patients (11 with AO and 15 without AO) and 14 healthy controls were cultured in the presence of RANKL and macrophage colony-stimulating factor for 9 days. Tartrate-resistant acid phosphatase-positive multinucleated giant cells (MGCs) containing 3 or more nuclei were counted as osteoclasts. Plasma levels and effects of vascular endothelial growth factor (VEGF) on osteoclast formation were evaluated.

RESULTS

SSc patients with AO formed significantly more osteoclasts after 9 days than did patients without AO (mean ± SD 142.4 ± 67.0 versus 27.2 ± 17.6 MGCs/well; P < 0.001) or healthy controls (mean ± SD 18.7 ± 27.0 MGCs/well; P < 0.001). No significant difference in osteoclast formation was noted between the patients without AO and healthy controls. Plasma levels of VEGF were higher in SSc patients with AO compared to those without (mean ± SD 142.4 ± 69.6 pg/ml versus 88.1 ± 38.2 pg/ml; P < 0.005) or healthy controls (54.2 ± 24.6 pg/ml; P = 0.018). Priming with VEGF-A for 24 hours significantly increased osteoclast generation by 5.3 ± 1.9 fold (P = 0.0018). The radiographic extent of AO was associated with increased osteoclast formation (Spearman's ρ = 0.741, P = 0.01).

CONCLUSION

Our findings indicate that increased osteoclast formation and higher VEGF levels may contribute to AO in SSc patients. Further studies are needed to elucidate whether targeting osteoclastogenesis may provide a specific therapeutic option for SSc-associated AO.

Ulcero-osteolytic lesions in a woman with type 2 diabetes and carpal tunnel syndrome: A case report and literature review

We describe the case of a 73-year-old woman with type 2 diabetes presenting with ulcers and ostelytic lesions on distal phalanges of left hand, who was diagnosed with the rare "ulcero-mutilating" variant of carpal tunnel syndrome. A review of literature on cutaneous manifestations associated with the syndrome is also presented.