This rare and comparatively unimportant condition occurs on the face especially on the forehead, though it may be found elsewhere. It consists of numerous pin- head to split-pea-sized papules or nodules imbedded in the skin and raised slightly above it. They are of lemon-yellow color, of a translucency resembling a drop of serum. When incised the contents appear as a yellow gelatinous substance.
Etiology and Pathology. – The causes are unknown. It chiefly occurs in middle and adult life, presents no subjective symptoms and does not influence the general health. Exposure to cold weather and severe precursory headaches or neuralgia have been noted in an etiological sense. The pathological findings may be summarized as a localized colloid degeneration of the cells and connective tissue of the corium, without involvement of the sebaceous glands.
Diagnosis. – Milium is usually white, lacks the vesiculoid look of colloid degeneration and its sebaceous contents can be easily demonstrated. Hydrocystoma occurs only in hot weather or from exposure to moist heat, and on pricking one of its lesions a clear liquid will escape. Xanthoma is usually confined to the neighborhood of the eyelids; its lesions are a deeper yellow and never simulate the vesicular type like colloid growths. The lesions of multiple benign cystic epithelioma are disseminated over the body, often congenital in origin, and are seldom yellowish in color.
Prognosis and Treatment. – The condition is progressive and does not tend to disappear. These growths may be removed by electrolysis or by the curette. I prefer solidified carbon dioxid with moderate pressure for 40 seconds. Rarely internal treatment is indicated. For this purpose I have found Baryta carb. or iodid useful.