Milium is a commonly occurring benign cyst that is filled with a substance called keratin. This is a condition very typically seen in but not limited to children and is called primary Milia. It occurs in adults as well. Milium is described as small epidermoid cysts. These are derived from what is called the pilosebaceous follicle. It is called secondary Milia when it is observed in disorders of blistering, usually following dermabrasion. Secondary Milia leads to the damage of the pilosebaceous unit.
They appear as 1-2 mm domed bumps which have a white to yellow appearance that are neither painful nor itchy. For primary Milia, the areas or locations that usually appears is around the eyes, nose, cheeks and forehead in both infants and adults. It could also appear on the upper palate on the inside of the mouth in infants. This type of Milia is called Epstein's pearls. This is a common condition in infants and occurs in up to 85% of them.
For secondary Milia, the locations where it may appear include but are not limited to any area on the body where a skin condition already is present. On the face, especially with people who have had damage from too much skin exposure.
To explain the causes in simple terms, the dead skin cells that are built up as a layer on our skin sometimes do not slough off easily and they accumulate and give rise to Milia. It is not considered a disease, rather a condition where the accumulation of these cells due to the thickening of the epidermis or any of the other reasons listed below cause it to form a trap. For instance, when the sebaceous glands are not fully developed they are believed to give rise to Milia which in turn explains the high prevalence of this condition in newborn babies.
The causes of secondary Milia however are considered to be due to the disruption of sweat ducts following trauma or blistering. Milia has also been described as an arising association with other disorders such as inherited or / and acquired epidermolysis bullosa, bullous lichen planus, bullous pempigoid and burns. Skin that has experienced trauma due to dermabrasion and or radiotherapy has also shown Milia formation. Secondary Milia is also caused by following contact dermatitis. Milia may also be caused after the treatment of cutaneous leishmaniasis. In cases of using a topical nitrogen mustard ointment in the treatment for the plaque stage of mycosis fungoides has also given rise to Milia.
Secondary Milia is described after the use of high potency topical corticosteroid usage as well.
The conditions of both multiple eruptive and primary Milia are considered to be familiar disorders with an autosomal dominant inheritance.
To prevent Milia, microdermabrasion is an effective method. A glycolic acid treatment also proves beneficial for the removal of dead cells from the skin regularly. A doctor can be consulted in regarding the use of formulations of Vitamin A to peel off skin cells on the surface and also to clean the dead skin cells. Protection from the sun is also a good way of prevention as sun exposure thickens the dermis. Avoid the use of heavy cosmetics and oil based formulations of sun screen as they block the skin.
For the treatment of Milia, there has been no effectiveness in the use of topical or systemic medicines. There are a few reports of success in the usage of topical isotretinoin, oral etretinate etc in the treatment of Milia and plaque. However, these are limited to single case reports.
Milia is best left alone and in cases where the patient requests for treatment, an incision with a needle of cutting edge and a manual expression of contents proves to be the most effective. This procedure is performed without local anaesthesia. It has also been reported that the use of a paper clip has been used successfully to express the contents of the cysts.