Highly increased urinary 1-hydroxypyrene excretion rate in patients with atopic dermatitis treated with topical coal tar

• Published in: Archives of Dermatological Research 2002-07, Vol.294 (4), p.168-171
• Main Authors: VEENHUIS, Rob T, VAN HORSSEN, Jack, BOS, Rob P, ANZION, Rob B. M, VAN DER VALK, Pieter G. M
• Format: Article
• Language: English
• Subjects: Absorption; Administration, Cutaneous; Adult; Allergic diseases; Animals; Biological and medical sciences; Body Water - metabolism; Carcinogens - administration & dosage; Carcinogens - adverse effects; Carcinogens - pharmacokinetics; Coal Tar - administration & dosage; Coal Tar - adverse effects; Coal Tar - pharmacokinetics; Dermatitis, Atopic - drug therapy; Dermatitis, Atopic - metabolism; Dermatitis, Atopic - urine; Epidermis - metabolism; Female; Humans; Immunopathology; Male; Medical sciences; Middle Aged; Pyrenes - metabolism; Risk Factors; Skin allergic diseases. Stinging insect allergies
• ISSN: 0340-3696; 1432-069X
• DOI: 10.1007/s00403-002-0311-5

Coal tar preparations, as used in dermatological practice, contain numerous polycyclic aromatic hydrocarbons of which many are proven animal carcinogens. Increased urinary 1-hydroxypyrene excretion in patients with atopic dermatitis treated with topical coal tar preparations has been demonstrated. Little is known about the relationship between the dermal uptake of polycyclic aromatic hydrocarbons on the one hand and the amount of tar applied to the skin, the total body area affected, the condition of the epidermal barrier and the severity of the dermatitis on the other. We compared urinary 1-hydroxypyrene excretion rate with these variables. The urinary 1-hydroxypyrene excretion rate was highly dependent on the total amount of tar applied to the skin and the total body area affected, and less on the severity of the atopic dermatitis or the condition of the epidermal barrier. Exposure to therapeutic doses of coal tar leads to much higher rates of urinary 1-hydroxypyrene excretion than occupational exposure. Because of the potential carcinogenicity of coal tar, as clearly demonstrated both in animal studies and from occupational exposure, careful consideration should be given to the use of coal tar preparations in dermatological practice. However, the risk of short-term high exposure is unknown. Restriction of the use of coal tar should be based on epidemiological studies and/or appropriate risk models taking into account its relative safety established over many years of clinical use.