This may be perfumed with oil of anise, five or ten drops to the ounce. It may be applied diluted with two or four parts of water or full strength, and is to be rubbed into the skin with a flannel rag, after which the parts are to be bathed with water and some emollient oil or ointment applied.
Treatment is usually effective in removing the lesions, but, unfortunately, in the majority of cases, relapses sooner or later occur. It may be said relapses are the rule. The prognosis will depend upon the case.
Pityriasis Rosea.
Pityriasis rosea, known also as pityriasis maculata et circinata, is an inflammatory disease, occupying chiefly the trunk, characterized by discrete or confluent pinkish or reddish macular or slightly raised lesions varying in size from a small to a large coin. They are rounded in form, but by coalescence may assume irregular shapes and considerable size, as in the case of psoriasis. They are circumscribed, usually clearly defined, superficially seated, of a bright rosy, pinkish, or reddish hue, which sooner or later fades and is followed by yellowish, salmon-colored, or rusty tints. The surface of the lesions is from the beginning dry, and as the process advances furfuraceous or flaky scaling sets in, similar to that observed in tinea versicolor and in tinea circinata. This feature is more marked about the border, the process inclining to recover in the centre and to spread on the periphery, after the manner of tinea circinata. The skin is only slightly, if at all, thickened. At times there is slight burning or itching, but more frequently subjective symptoms are altogether wanting.
The course of the affection is variable, in many instances lasting from one to several months, while in exceptional cases it is more acute. It tends to spontaneous recovery, and is to be viewed as a mild disease, notwithstanding that the lesions at times, by their redness and size, indicate considerable cutaneous disturbance. It is met with in all ages, in our own experience more frequently in adults than in children, and occurs in both sexes and in those possessing average general health. It is one of the rarer cutaneous diseases, and is not contagious.
It is to be distinguished from ringworm of the body, from tinea versicolor, and from the macular syphiloderm, all three of which diseases it at times closely resembles. It possesses some of the peculiar features which characterize the vegetable parasitic diseases, but in some respects it differs from them in its behavior. The microscope fails to reveal fungus. Concerning treatment there is but little to be said, as the process inclines in most cases to spontaneous disappearance. Mildly stimulating ointments or baths, as in eczema, may be prescribed. When involution sets in recovery usually takes place rapidly.
Pityriasis Rubra.
Pityriasis rubra is an inflammatory disease, usually pursuing a chronic course, characterized by redness and abundant and continuous epidermic exfoliation. It usually develops rapidly, beginning as small, red, scaly patches. It may make its appearance on one or more regions, the spots increasing in size rapidly, and coalescing to form large patches. In a variable time the whole or a large portion of the entire surface is involved, the skin being of a pale or violaceous red color and covered with thin whitish or grayish lamellar scales. These are abundant, and are rapidly formed, cast off and replaced by new, the exfoliation being, as a rule, in the form of flakes. Thickening of the skin seldom occurs. The surface when deprived of the scales is hyperæmic and shining in appearance. The disease usually involves the whole surface. Oedema, especially of the limbs, and stiffness of the joints are sometimes observed. The disease is superficial in character, rarely involving more than the upper cutaneous layers, and is always dry. Fissuring is only exceptionally seen.
As a rule, the subjective symptoms are slight, burning and itching, if present, seldom being violent. Symptoms of constitutional disturbance may or may not be present, but chilliness is often complained of. The disease generally occurs in adults, is acute or chronic, usually the latter, with a tendency to relapses. Being a rare affection, the etiology is obscure. Anatomically, there is found more or less marked cell-infiltration of the cutaneous tissues, especially noticeable in the rete and upper layer of the corium. In severe cases the papillæ are not distinguishable; the same may be said of the sweat and sebaceous glands.
Erythematous and squamous eczema and psoriasis bear resemblance to the disease. Its superficial nature, wide or universal distribution, absence of infiltration, character and rapid formation of the scales, and the slight itching or burning will serve to differentiate it from eczema. In psoriasis the whole surface is rarely if ever involved, while there is more or less thickening of the corium, and the scales are thicker and imbricated. It can scarcely be confounded with lichen ruber or with pemphigus foliaceus.