Ichthammol is a dark fluid that is used in low concentrations of between 10 and 20 percent in ointments to treat skin disorders, according to Drugs.com. It acts as a mild irritant, stimulant and antiseptic, helping to reduce inflammation of the affected skin.
The ointment is used to treat a variety of skin conditions, notably eczema, notes Patient.co.uk. It reduces itching and also reduces excessive hardening and thickening of the skin associated with that condition. It should only be used externally and under the guidance of a doctor or pharmacist. There are few known side effects, although allergy to one or more of the ingredients may cause irritation. This ointment is not known to affect other medicines, explains NetDoctor.co.uk.