Colloid Degeneration Of The Skin

 Synonyms.    Colloid milium, colloid pseudomilium, miliary colloidoma, hyaloma.

         This is a rare disease which usually occurs on the face or the dorsal surfaces of the hands, but may occur at any other site. It generally begins in early childhood as cream-colored or yellowish, pinhead to split-pea-sized, rounded, pellucid papules. The lesions gradually develop and spread over the cheeks, forehead and nose, and on the backs of the hands. The papules are of a firm consistency and do not coalesce but are frequently grouped. Although they resemble vesicles, usually nothing can be expressed from them when incised. However, some authors state that small amounts of a gelatinous substance can be squeezed out. The disease causes no symptoms but is persistent and seldom disappears; although sometimes it does as in the case pictured in Figure a. This photograph was made when the patient was 8 years of age. Now at the age of 20, there is scarcely a trace of the disease. Her sister had the same condition and is likewise cured.

     The exact cause of the disease is unknown but there is increasing evidence that it is provoked in some cases by severe sunburn. Colloid degeneration of the skin is to be differentiated from milium, hydrocystoma, adenoma sebaceum, syringocystadenoma, and multiple steatomata.

     The histopathology of one of our cases, as described by Dr. G. F. Machacek, is typical: "These sections of skin showed a thin keratin layer which had been lifted from the underlying epidermis and which disclosed processes corresponding to the keratin within the numerous follicular funnels. The follicles were small and apparently represented follicles of lanugo hairs. The epidermis was thin. Processes of this epidermis penetrated the corium and connected with one another, thus forming roughly oval patterns. Within these enclosures there was seen a degenerated connective tissue composed of swollen bundles, separated by clefts. This tissue was pink. The areas were fairly cellular. With Congo red and methyl violet stains no evidence of amyloid was produced. Sections stained with scarlet red showed the areas of degeneration, which were enclosed within the epidermal pattern, to be a muddy brown color due to the deposition of small droplets of fat. The area of degeneration extended one-third to one-half the thickness of the corium. The corium beneath, though relatively normal in texture, was the site of edema and a moderate chronic inflammatory process, the infiltrating cells of which were chiefly mononuclear. The picture was that of so-called colloid milium but showed a definite lipid deposition such as is described under lipid proteinosis."