Results of Histidine (His) Supplementation in a Case of Severe Nummular Eczema (NE)

Abstract

Abstract Objectives NE (coin-shaped, severely pruritic skin lesions) is an idiopathic, histologically indistinguishable form of atopic dermatitis (AD). NE is chronic, relapsing and debilitating. Treatment is limited to skin moisturizers and anti-inflammatory agents. Recurrence is common. Recent studies suggest that lack of the protein, filaggrin (FLG) and its derivative natural moisturizing factors (NMFs) play a role. Because FLG is a His-rich compound, l-His supplementation (LHS) may provide a nutritional NE option. In this report, we present a patient with severe, resistant NE who responded to LHS. Methods The patient is a 57 yo female with NE, unresponsive to topical emollients, topical and oral steroids, oral antihistamines, phototherapy, topical calcineurin inhibitors and immune modulating agents. She attempted nutritional options by eliminating food allergens (dairy, nuts, wheat, eggs) and followed an anti-inflammatory diet. Because these had only modest effects, a trial of oral LHS (8 gm/d) was begun. After 4 months on therapy NE improved significantly. Lesions diminished in size and number. The pruritus was nearly eliminated. Liver and kidney function remained normal. Results NE is a debilitating form of AD. Current therapy is essentially palliative, relying on the use of topical emollients and anti-inflammatory agents. Phototherapy and even systemic immune modulation provide only partial results. Standard nutritional approaches are generally of little value. In this case, LHS was attempted after all other options failed. LHS had a dramatic effect on the patient's NE, markedly reducing the pruritus and visibly improving the rash. The NE lesions became smaller and less numerous. LHS was well tolerated without notable adverse effects. His is an essential amino acid whose deficiency results in negative nitrogen balance, anemia and decreased histamine and carnosine production. His is a major component of FLG (∼10%). FLG degrades into NMFs which contribute to skin hydration and stratum corneum acidity. LHS is believed to increase FLG and NMF production. Conclusions LHS produced symptomatic improvement in a case of severe, treatment-resistant NE. We believe this effect was the result of increased FLG production due to LHS, with subsequent improvements in NMFs and skin hydration. LHS may be a therapeutic option for selected cases of resistant NE. Funding Sources None.