back. The color of blackheads is caused by melanin and oxidized oil, not dirt. A
blackhead is of cosmetic rather than medical importance. The contents of the lesion
may be removed with an extractor that takes out the plug and improves cosmetic
appearance. Often, however, the blackhead returns in full flower within a month.
(2) Milia (whitehead). A milia or whitehead occurs when a sebaceous duct
is blocked with horny materials. These skin lesions, of cosmetic importance only, are
small, superficial, keratinous cysts. To remove these cysts, make a small opening with
a scalpel and remove the cyst with a comedo extractor.
(3) Sebaceous cyst. A sebaceous cyst forms as a result of a blocked
sebaceous duct which continues its activity. In puberty, the growth-pattern of
sebaceous glands changes often cause an increase in sebaceous cysts.
(4) Wen. A wen is a common type of epidermal cyst, a sebaceous cyst,
found on the scalp or scrotum. This type of sebaceous cyst is a slow-growing cyst
containing follicular, keratinous, and sebaceous material. When palpated, the cystic
mass is firm, globular, moveable, and nontender. It seldom causes discomfort unless it
is infected. When punctured, the contents of the cyst are found to be cheesy, often fetid
formed of epithelial debris and greasy material with soft keratin present. Sometimes,
calcium deposits may be found. If the wen is small, the contents may be expressed by
making a tiny stab incision. If the wen is large, a small incision can be made and the
contents evacuated. Then, remove the cyst wall with a curette or hemostat. The wall of
a large cyst must be removed to prevent recurrence of the cyst.
(5) Folliculitis (ingrown hair). Usually caused by Staphylococcus
aureus, folliculitis is a superficial or deep bacterial infection and irritation of the hair
follicle. The lesion is made up of a superficial pustule or inflammatory nodule
surrounding a hair. Infected hairs can be easily removed. When the hair follicles are
deep in the skin (for example, the bearded region), folliculitis may become chronic.
Stiff hairs in the bearded area of the skin may come out of the hair follicle, curve, and
reenter the skin. This produces a chronic, low-grade irritation without major infection.
To prevent folliculitis, aggravating factors or irritations must be corrected.
(6) Furuncle (boil). A furuncle is a deep-seated infection with a single core;
the infection involves the entire hair follicle and adjacent subcutaneous tissue. This
lesion becomes a pustule 5 to 30 mm in diameter with central necrosis that discharges
a core and liquid. Furuncles usually occur in hairy parts of the body where there is
irritation, friction, pressure, moisture, or oily skin. Although furuncles occur frequently
on the neck, breasts, face, or buttocks, these skin lesions are most painful when they
occur in skin that is closely attached to underlying structures; for example, the nose,
ear, or fingers. Furuncles can occur over and over, often in healthy young people.
(7) Carbuncle. A carbuncle is a staph infection with multiple tracts (several
furuncles) that extend into the subcutaneous tissue. The furuncles have developed in
adjoining hair follicles, developing more slowly than one furuncle and sometimes