Page 52 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 2-25 Integumentary System

Congenital milia in a newborn. This is a
common incidental finding.

MILIA

Milia are tiny (1-3 mm), superficially located epidermal
inclusion cysts. They typically have a characteristic
porcelain-white color. One often encounters a patient
with a solitary milium or multiple milia. These tiny skin
growths are entirely benign and cause no harm to the Milia in an adult. Small white papules just
patient. underneath the epidermis. They represent
Clinical Findings: Milia are tiny epidermal inclusion small cysts and are very commonly located
cysts located superficially in the epidermis. They do not on the eyelids.
have an appreciable overlying central punctum. They
occur in all races, at all ages, and equally in males and
females. Primary milia occur without an underlying
skin disorder. Secondary milia occur because of an
underlying skin disorder, most often a subepidermal
blistering condition. As the subepidermal blister heals,
it is not uncommon to see the development of milia in
the area of the previous blister. As an example, patients
with porphyria cutanea tarda develop subepidermal
blisters and typically heal with scarring and milia for-
mation. Occasionally, a milium can have a somewhat
translucent appearance and should be biopsied to rule
out a basal cell carcinoma or an intradermal nevus.
In adults, milia most commonly occur on or around
the eyelids. Up to half of all newborns have milia. These
are typically located on the head and are termed more
specifically congenital milia. They almost always resolve A small well-circumscribed cyst is seen
on their own without therapy, and therapy should be within the dermis. The lining is stratified
withheld to provide time for spontaneous resolution. squamous epithelium with a granular
Unique forms of milia eruptions have been described cell layer.
in the literature, including eruptive multiple milia,
grouped milia, and generalized milia. Eruptive milia
manifest over a period of weeks, with the appearance of
10 to 100 milia. This has been described in teenagers
and adults. Grouped milia and milia en plaque are rare;
these terms are used, respectively, to describe a nodular
grouping and a plaque-like grouping of milia.
Certain genetic syndromes show an association with
milia, the best recognized one being Bazek’s syndrome.
This syndrome is defined as a constellation of milia,
basal cell carcinomas, hypotrichosis, and follicular atro- amount of keratin debris. There is typically no sur- to the attention of the patient for education. Patients
phoderma. A few other genetic syndromes that have rounding inflammation in a primary milium. are often unaware of the milia. If a patient is bothered
milia are the Rombo syndrome, familial milia syn- Pathogenesis: The cause is unknown, but the cysts by the appearance of the cyst, extraction with a come-
drome, and atrichia with papular lesions. Many other are believed to be derived from the hair follicle, seba- done extractor after creating a tiny (1-mm) incision
syndromes with milia have been reported. ceous gland, or eccrine gland epithelium. Secondary with a no. 11 blade is all that is required for removal.
Histology: Milia are tiny cysts in the superficial epi- milia occur after subepidermal blistering or trauma that Once the cyst is removed, it almost never recurs,
dermis. The cyst has a true lining of stratified squamous interrupts the epidermal-dermal junction. although other milia may develop after extraction.
epithelium. A granular cell layer is present in the cyst Treatment: No therapy is required. Most milia are Treatment of congenital milia in infants is not required
wall lining. The center of the cyst is filled with a small found during routine skin examinations and are brought because they almost all resolve spontaneously.

38 THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS