Differential Diagnosis for Excessive Perspiration

The patient's complaint of excessive perspiration after dinner, which started after the initiation of medications for depression, suggests several potential causes. Here's a categorized differential diagnosis:

• Single Most Likely Diagnosis

  • Medication-induced hyperhidrosis: The recent introduction of olanzapine, paroxetine, and lamotrigine for depression treatment is the most likely cause. These medications, especially selective serotonin reuptake inhibitors (SSRIs) like paroxetine, are known to cause hyperhidrosis as a side effect. Olanzapine, an atypical antipsychotic, can also contribute to this symptom.

• Other Likely Diagnoses

  • Hypoglycemia: Although the patient's sugars remain normal when checked, it's possible that the patient is experiencing hypoglycemic episodes, especially after dinner, which could be causing the excessive perspiration. This is more likely if the patient's diet or anti-diabetic medication regimen has changed recently.
  • Anxiety or stress response: The patient's recent diagnosis of depression and the initiation of new medications could be causing anxiety or stress, leading to excessive perspiration.
  • Autonomic dysfunction: As a side effect of diabetes or its treatment, or even as a result of the depression itself, autonomic nervous system dysfunction could lead to abnormal sweating patterns.

• Do Not Miss Diagnoses

  • Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic excessive sweating, among other symptoms like hypertension and palpitations. Although unlikely, missing this diagnosis could be catastrophic.
  • Thyroid disorders: Hyperthyroidism can cause excessive sweating. Given the patient's other health issues, it's crucial not to overlook thyroid function, even though the patient's main complaint is sweating.
  • Infections: Certain infections can cause night sweats or excessive perspiration, although the patient's symptoms are specifically post-dinner, it's essential to consider infectious causes, especially if other symptoms develop.

• Rare Diagnoses

  • Neurological disorders: Conditions like multiple system atrophy or other neurodegenerative diseases can affect autonomic function, leading to abnormal sweating patterns. These are rare and would typically be accompanied by other neurological symptoms.
  • Gustatory sweating (Frey's syndrome): A rare condition that can cause sweating in response to food, which might fit the post-dinner timing of the patient's symptoms, although it's more commonly associated with specific foods and facial sweating.
  • Drug withdrawal: If the patient has been taking any medications that could cause withdrawal symptoms leading to sweating (less likely given the current medication list), this should be considered, especially if there have been any recent changes in medication dosages or schedules.