Trigeminal Neuralgia: This condition is characterized by sudden, severe, and stabbing pain or tingling sensation in parts of the face, which can be triggered by light touch. The fact that the tingling is localized to one side of the face, from below the eyelid to the jaw, aligns with the distribution of the trigeminal nerve. However, the chronic nature and the presence of nausea might suggest other underlying causes.

Migraine: Migraines can cause facial tingling or numbness, often accompanied by nausea and vomiting. The tingling could be part of the aura phase or a symptom of the migraine itself.
Temporal Arteritis: This condition involves inflammation of the blood vessels in the head, leading to pain, tingling, or numbness in the face, and can also cause nausea. However, it typically affects older adults.
Multiple Sclerosis (MS): MS can cause a wide range of neurological symptoms, including facial numbness or tingling, due to lesions in the central nervous system. Nausea can also occur, especially if there are lesions affecting the brainstem.

Stroke or Transient Ischemic Attack (TIA): Although less likely given the chronic nature of the symptoms, it's crucial to consider stroke or TIA, especially if there are sudden changes or if the symptoms worsen. Facial tingling can be a sign of a stroke, particularly if accompanied by other symptoms like weakness, vision changes, or difficulty speaking.
Brain Tumor: A tumor in the brain, especially one affecting the trigeminal nerve or brainstem, could cause facial tingling and nausea. The chronic nature of the symptoms could suggest a slowly growing tumor.
Lyme Disease: Neurological manifestations of Lyme disease can include facial numbness or tingling, among other symptoms. Given its potential severity and the importance of early treatment, it should not be overlooked.

Sarcoidosis: This autoimmune disease can affect various parts of the body, including the nervous system, leading to symptoms like facial numbness or tingling. It's less common but should be considered if other diagnoses are ruled out.
Vitamin Deficiencies (e.g., Vitamin B12 Deficiency): Certain vitamin deficiencies can cause neurological symptoms, including numbness or tingling in the face. While less likely to cause localized facial tingling, they are important to consider, especially if there are other systemic symptoms.
Peripheral Neuropathy: This condition involves damage to the peripheral nerves and can cause tingling or numbness. It's more commonly associated with diabetes or other systemic conditions but could potentially cause localized symptoms if a specific nerve branch is affected.