Are You Confident of the Diagnosis?
What you should be alert for in the history
Essential fatty acid deficiency occurs in individuals receiving total parenteral nutrition (TPN) without lipid supplementation, in patients with a gastrointestinal disorders resulting in severe fat malabsorption such as cystic fibrosis and in systemic conditions, including acrodermatitis enteropathica, peripheral vascular disease, multiple sclerosis, alcoholism, anorexia nervosa, AIDS, and protein energy malnutrition (kwashiorkor and marasmus).
Characteristic findings on physical examination
Affected individuals develop a number of cutaneous findings, including severe generalized dermatitis (flakey paint dermatitis), severe xerosis, peri-orificial dermatitis (acrodermatitis-like rash), alopecia, and ichthyosis. Patients may also show failure to thrive, growth retardation, alopecia with light colored hair, thrombocytopenia, increased capillary fragility, poor wound healing, fatty liver, and increased susceptibility to infection.
Expected results of diagnostic studies
The skin biopsy findings vary with the clinical appearance of the rash and are similar to other “deficiency dermatoses.” Specimens may show spongiosis, psoriasiform epidermal hyperplasia, hyperkeratosis with parakeratosis, a diminished granular cell layer, individual keratinocycte necrosis, pallor of the superficial epidermal layer, and vacuolar changes.
The diagnosis is confirmed by decreased levels of linoleic, arachidonic, and eicosatrienoic acids and an eicosatrienoic:arachidonic acid ratio of greater than 0.4 or linoleic:arachidonic acid ratio of greater than 2.3. These laboratory values are readily available from the Mayo Clinic; most labs would likely send this test to the Mayo Clinic.
Who is at Risk for Developing this Disease?
Patients receiving lipid-deficient TPN and malnourished patients, such as those with cystic fibrosis, are at risk for developing essential fatty acid deficiency. Lipid-deficient TPN should be of historical significance only, as all TPN contains these important nutrients now. Infants fed formula low in linoleic acid, such as skim milk formula, can develop signs of essential fatty acid deficiency.
What is the Cause of the Disease?
Essential fatty acids (linoleic acid (v-6) and alpha-linolenic acid (v-3)) are necessary for normal physiology, but must be received from dietary sources. These essential fatty acids are important for a number of biochemical processes, including prostoglandin, thromboxane, leukotriene and lipoxin pathways. These pathways are critical to the normal functioning of multiple organ systems, including the brain, retina, liver, kidney, adrenal gland, and gonad. In the skin, essential fatty acids serve a central role in inflammation and epidermal barrier function.
Alpha linolenic deficiency can occur in isolation, resulting in visual disturbance and sensory neuropathy; usually AL and ALA deficiency occur together.
Essential fatty acids are found in vegetable oils, plant seeds, green leafy vegetables, soybeans, meats, eggs, and fish.
Systemic Implications and Complications
Systemic implications of essential fatty acid deficiency are widespread and include neurological (dementia, poor neurological development), visual, inflammatory, gastrointestinal (elevated hepatic enzymes), hematological (hemolytic anemia and thrombocytopenia) and endocrine system deficits.
Free fatty acid (FFA) deficiency results in poor growth and development; FFA usually occurs in the setting of generalized malnutrition and so isolating direct cause and effect is challenging.
Essential fatty acid deficiency can be prevented by the daily intake of essential fatty acids of at least 1% to 2% of the total energy requirement. Essential fatty acids can be administered orally, parenterally, and topically. The intake of essential fatty acids for children has to be roughly 2.7% of total calories. It is best to consult a pediatric specialist (geneticist, endocrinologist) after making this diagnosis.
Optimal Therapeutic Approach for this Disease
Patients with essential fatty acid deficiency should be evaluated for underlying systemic processes, including including acrodermatitis enteropathica, peripheral vascular disease,multiple sclerosis, alcoholism, anorexia nervosa, AIDS, and proteinenergy malnutrition (kwashiorkor and marasmus).
Infants with failure to thrive due to chronic malabsorption, such as those with cystic fibrosis should be evaluated for accompanying essential fatty acid deficiency. When the diagnosis is made by dermatology, usually it is in the setting of cystic fibrosis or chronic malabsorption due to GI disease; many of these patients are followed in multidisciplinary clinics.
Essential fatty acid deficiency can be prevented by the daily intake of essential fatty acids of at least 1 to 2% of the total energy requirement. Essential fatty acids can be administered orally and parentally. Topical application of sunflower oil has been utilized in select cases to treat essential fatty acid deficiency, however topical replacement is not adequate in all patients.
Patients with essential fatty acid deficiency respond readily to replacement of essential fatty acids and require infrequent monitoring after the underlying disorder is corrected. An essential fatty acid profile (should be ordered at baseline and follow-up visits in 1 month.
Unusual Clinical Scenarios to Consider in Patient Management
One should look for concomitant nutritional deficiencies, such as protein and zinc deficiency. Remember to inquire about fad diets.
What is the Evidence?
Gehrig, KA, Dinulos, JG. “Acrodermatitis due to nutritional deficiency”. Curr Opin Pediatr. vol. 22. 2010. pp. 107-12. (This article reviews the current evidence of nutritional dermatitis.)
Kim, YJ, Kim, M-Y, Kim, HO, Lee, M D, Park, YM. “Acrodermatitis enteropathica-like eruption associated with combined nutritional deficiency”. J Korean Med Sci. vol. 20. 2005. pp. 908-11. (These authors present an adult who developed a deficiency dermatitis due to a mixed nutritional deficiency after a Whipple procedure.)
Smit, EN, Muskieta, FAJ, Boersma, ER. “The possible role of essential fatty acids in the pathophysiology of malnutrition: a review”. Prostoglandins Leukot Essent Fatty Acids. 2004. pp. 241-50. (This article reviews nicely the role of fatty acids in physiological processes.)
Yashodhara, BM, Umakanth, S, Pappachan, JM. “Omega-3 fatty acids: a comprehensive rewiew of their role in health and disease”. Postgrad Med J. vol. 85. 2009. pp. 84-90. (This article focuses on the omega-3 fatty acids but reviews the clinically relevant roles of essential fatty acids in health and disease.)
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