An NPO postoperative patient on 2-in-1 PN for three weeks develops dermatitis, hair loss, anemia, and thrombocytopenia. What is the probable cause?

• A. Not receiving IVFE for 3 weeks
• B. Trace elements shortage three times weekly
• C. Receiving 20 kcal/kg per day from PN
• D. PN related cholestasis and fat malabsorption

Answer: (A)

Essential fatty acids must be supplied with PN to maintain skin, hair, immune function, and overall cell membrane integrity. When intravenous fat emulsions are omitted for a prolonged period, essential fatty acid deficiency (EFAD) develops, typically within 1–3 weeks in adults. The hallmark signs of EFAD—dermatitis and hair loss—are clearly present in this patient, and anemia and thrombocytopenia can accompany EFAD due to impaired hematopoietic function and membrane fragility from fatty acid deficiency. In a postoperative patient who is NPO and on PN without IV fat emulsion for three weeks, EFAD is the most likely cause of these findings.

Other possibilities would not fit this pattern as neatly. A calorie level of 20 kcal/kg per day does not cause these deficiency signs. A trace element shortage might lead to dermatitis and hair changes (e.g., zinc deficiency) but would not explain the timing and breadth of hematologic effects as cleanly. PN-related cholestasis and fat malabsorption imply fat being present but poorly utilized, with different clinical features such as liver-related signs and fat-soluble vitamin deficiency rather than the acute dermatitis and alopecia seen with EFAD.