A patient maintained on fat-free total parenteral nutrition for 5 weeks develops a scaly desquamating rash, alopecia, and thrombocytopenia. Which deficiency explains this presentation, and how much linoleic acid intake prevents it?

• A Zinc deficiency; 5 mg/day elemental zinc
• B Copper deficiency; 0.3 mg/day elemental copper
• C Vitamin C deficiency; 100 mg/day ascorbic acid
• D Essential fatty acid deficiency; about 2 to 4 percent of total calories as linoleic acid ✓

Explanation

Essential fatty acid deficiency arises when parenteral regimens omit lipid for weeks. Linoleic acid cannot be synthesised endogenously, and its absence produces the classic triad of scaly dermatitis, alopecia, and thrombocytopenia, often with impaired wound healing. Prevention requires roughly 2 to 4 percent of daily calories as linoleic acid. Zinc deficiency causes dermatitis too but presents with diarrhoea around the stoma and alopecia without thrombocytopenia.

Reference: Sabiston Textbook of Surgery, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.