This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
In all forms of dry, scaly, skin disease (whether syphilitic or not) warm baths (especially when made emollient and alkaline) and vapor-baths are useful. In acne, hot bathing or steaming opens up the glands and relieves congestion. In psoriasis, ichthyosis, lichen, prurigo, "pityriasis rubra," and chronic dry eczema and seborrhoea, for removing accumulated secretion or preventing contact of air, water compresses are serviceable. Hebra has tried the prolonged warm bath for from two hours to nine months at a time, in. some such cases, and in extensive burns, etc., and has ascertained that nutrition, respiration, and secretion go on in the continued bath in a normal manner (Medical Record, 1877). On the other hand, in some skins, and especially when the epidermis is removed, as it commonly is in acute eczema, water is apt to excite much irritation.