Vitamin B6 deficiency
Pyridoxal phosphate (PLP) is the most biologically active form of pyridoxine in the body.
Isolated vitamin B6 deficiency is uncommon and usually occurs in conjunction with other vitamin deficiencies. Alcohol use disorder; malabsorption syndromes; eating disorders, which result in general undernutrition; or medications (eg, isoniazid, theophylline, penicillamine, oral contraceptives) predispose patients to the development of pyridoxine deficiency.
Drugs induce vitamin B6 deficiency in various ways. For example, isoniazid binds to PLP, resulting in increased excretion of the active form of B6. Penicillamine inhibits vitamin B6-dependent enzymes. Oral contraceptives play a role in the increased turnover of vitamin B6.
Manifestations of pyridoxine deficiency are often nonspecific but may include fatigue, nausea, anorexia, paresthesia, depression, glossitis, dermatitis, peripheral neuropathy, and microcytic anemia. Severe vitamin B6 deficiency can result in seizures and personality changes characterized by irritability and confusion.
In infants, B6 deficiency may lead to diarrhea, seizures (pyridoxine-dependent seizures), and anemia.
E53.1 – Pyridoxine deficiency
386080007 – Vitamin B6 deficiency
Differential Diagnosis & Pitfalls
- Thiamine deficiency
- Folate deficiency
- Vitamin B3 deficiency
- Vitamin B12 deficiency
- Seborrheic dermatitis
- Candidiasis – satellite papules and/or pustules
- Inverse psoriasis – well-demarcated salmon-pink plaques
- Tinea cruris – annular scaly plaques
- Allergic or irritant contact dermatitis
- Acanthosis nigricans
- Lichen sclerosus
- Hailey-Hailey disease – macerated plaques with linear erosions
- Extramammary Paget disease
- Group A beta-hemolytic streptococcal intertrigo
- Langerhans cell histiocytosis
- Inverse lichen planus
- Granular parakeratosis
- Hidradenitis suppurativa
- Fox-Fordyce disease
Drug Reaction Data