ABSTRACT
Ichthammol is a complex product obtained by the sulfonation and ammoniation of shale oil, the distillation product of bituminous schists. It consists of 10% sulfur, 5–7% ammonium sulfate, hydrocarbons, nitrogenous bases, acids and derivatives of thiophene. The allergen is said to be present in the water- and cyclohexane-soluble fraction. Ichthammol is available in OTC products as an active ingredient for the treatment of skin disorders such as eczema, psoriasis and boils as it is thought to exhibit anti-inflammatory, antibacterial and antimycotic properties. In Leuven, Belgium, in the period 1990–2014, iatrogenic contact dermatitis was diagnosed in 2600 individuals (17% of the total patch test population). In Warsaw, Poland, in the period 1967–1970, 836 selected patients (selection criteria unknown) were patch tested with ichthammol 5% pet and there were 2.7% positive reactions; their relevance was not mentioned.
