From the Guidelines
The correct answer is (a) zinc deficiency, as it is a well-established cause of alopecia in patients receiving prolonged total parenteral nutrition (TPN). Prolonged TPN without adequate zinc supplementation can lead to zinc deficiency, which is associated with alopecia, skin rash, growth retardation, and impaired wound healing, as noted in the espen micronutrient guideline 1. Zinc deficiency affects cells involved in both innate and adaptive immunity, and its deficiency can lead to impaired immune function, making patients more susceptible to infections 1. The espen micronutrient guideline recommends measuring zinc levels in patients on long-term parenteral nutrition every 6-12 months, highlighting the importance of monitoring zinc status in these patients 1. While essential fatty acid deficiency can also cause alopecia, zinc deficiency is a more direct and well-documented cause of hair loss in the context of prolonged TPN, as supported by the guideline 1. Some key points to consider in preventing zinc deficiency in patients on TPN include:
- Monitoring zinc levels regularly, as recommended by the espen micronutrient guideline 1
- Ensuring adequate zinc supplementation in TPN formulations
- Being aware of the increased risk of zinc deficiency in patients with certain medical conditions, such as short bowel syndrome, bariatric surgery, and chronic pancreatitis, as noted in the guideline 1.
From the FDA Drug Label
At plasma levels below 20 mcg zinc/100 mL dermatitis followed by alopecia has been reported for TPN patients. The answer is: (a) zinc deficiency 2
From the Research
Possible Causes of Alopecia with Prolonged Total Parenteral Nutrition
- Zinc deficiency: Studies have shown that zinc deficiency is a common cause of alopecia in patients receiving total parenteral nutrition 3, 4, 5. Zinc plays a crucial role in hair growth, and its deficiency can lead to hair loss.
- Selenium deficiency: Selenium deficiency has also been linked to alopecia in some infants on parenteral nutrition, and supplementation with selenium has been shown to relieve hair loss in these cases 3.
- Essential fatty acids deficiency: Although deficiencies of essential fatty acids resulting in alopecia have been largely eliminated by regular use of lipid-containing parenteral nutrition, it is still a possible cause of hair loss 3.
- Other micronutrient deficiencies: Other micronutrient deficiencies, such as iron depletion, biotin deficiency, and copper deficiency, may also contribute to hair loss in patients receiving total parenteral nutrition 3, 6, 7.
Evidence from Studies
- A study published in 2010 found that zinc is the most frequently suspected deficiency causing hair loss in patients receiving total parenteral nutrition, and that zinc therapy can lead to rapid clinical responses 3.
- A study published in 1983 reported on the clinical course of three patients who developed zinc deficiency while receiving total parenteral nutrition, and found that treatment with intravenous zinc chloride or oral zinc sulfate led to a rapid and dramatic improvement in symptoms 4.
- A review published in 2015 discussed the physiology of zinc, the consequences of its deficiency, and the assessment of its status, and recommended generous zinc provision from the start of parenteral nutrition 5.