Cervical Spondylosis: This condition is a common cause of bilateral paresthesias in the upper extremities, upper chest, and neck due to compression of nerve roots in the cervical spine. The symptoms can be exacerbated by age-related wear and tear, making it a likely diagnosis in a 49-year-old male.

Multiple Sclerosis: An autoimmune disease that affects the central nervous system, potentially causing paresthesias in various parts of the body, including the upper extremities and neck.
Vitamin B12 Deficiency: A condition that can lead to neurological symptoms, including paresthesias, due to the importance of vitamin B12 in the synthesis of myelin.
Hypothyroidism: In some cases, hypothyroidism can cause neurological symptoms, including paresthesias, possibly due to the metabolic effects on the nervous system.

Spinal Cord Compression: Conditions such as tumors or abscesses compressing the spinal cord can cause bilateral paresthesias and are medical emergencies requiring prompt intervention.
Guillain-Barré Syndrome: An autoimmune disorder that can lead to rapid onset of muscle weakness and paresthesias, potentially progressing to life-threatening respiratory failure if not recognized and treated promptly.
Stroke or Transient Ischemic Attack (TIA): Although less common for causing bilateral paresthesias without other neurological deficits, it's crucial to consider vascular events, especially given the potential for serious outcomes.

Sjögren's Syndrome: An autoimmune disorder that can affect various parts of the body, including the nervous system, potentially causing paresthesias.
Lyme Disease: In its later stages, Lyme disease can cause neurological symptoms, including paresthesias, although this would be less common and typically accompanied by other symptoms.
Sarcoidosis: A condition that can affect multiple systems in the body, including the nervous system, leading to a variety of neurological symptoms, including paresthesias.