Differential Diagnosis for Body Odour

The patient presents with a long-standing complaint of bad body odour, particularly from the armpits, which has been worsening over time and is causing significant distress. The following differential diagnoses are considered:

• Single Most Likely Diagnosis
  • Hyperhidrosis: This condition is characterized by excessive sweating, which can lead to body odour. The patient's history of noticing the odour primarily from the armpits and the ineffectiveness of deodorants support this diagnosis. Hyperhidrosis can be primary (idiopathic) or secondary to other conditions, but given the patient's otherwise unremarkable medical history, primary hyperhidrosis is a strong consideration.
• Other Likely Diagnoses
  • Apocrine Bromhidrosis: This condition involves an abnormality in the apocrine glands, leading to the production of a type of sweat that is high in protein and lipids, which can decompose and cause a strong odour. The patient's description of the odour coming from the armpits, where apocrine glands are primarily located, makes this a plausible diagnosis.
  • Fox-Fordyce Disease: A rare condition but considered here due to the patient's history of a rash and boil in the armpits. It affects the apocrine glands, leading to itchy, domed bumps or papules, and can cause body odour.
• Do Not Miss Diagnoses
  • Diabetes Mellitus: Although the patient does not have a known medical history, uncontrolled diabetes can lead to changes in body odour due to the production of acetone. Missing this diagnosis could have significant health implications.
  • Thyroid Disorders: Both hyperthyroidism and hypothyroidism can affect sweat production and body odour. These conditions require medical intervention to prevent long-term health consequences.
  • Kidney or Liver Disease: Advanced kidney or liver disease can lead to changes in body chemistry that result in noticeable changes in body odour. These conditions are potentially life-threatening if not addressed.
• Rare Diagnoses
  • Trimethylaminuria (Fish Odour Syndrome): A genetic disorder that leads to the inability to break down trimethylamine, resulting in a strong fish-like body odour. This condition is rare but should be considered in cases of persistent, unexplained body odour.
  • Isotretinoin-Induced Hyperhidrosis: Although the patient is not on any medications, including isotretinoin, this is a rare side effect of the drug that could be considered if the patient were to start such treatment in the future.

Each of these diagnoses should be considered and investigated further through a combination of clinical evaluation, patient history, and potentially laboratory tests to determine the underlying cause of the patient's body odour.