SCROTAL SKIN DISEASES I: CHEMICAL
AND INFECTIOUS
Contact dermatitis (dermatitis
venenata) is a localized rash or irritation of the skin caused by contact with
a foreign substance. Only the superficial regions of the skin are affected,
including the epidermis and the outer dermis. Unlike contact urticaria, in
which a rash appears within minutes of exposure and fades away within minutes
to hours, contact dermatitis takes days to fade away. The most common causes of
allergic contact dermatitis are poison ivy, poison oak, and poison sumac.
Common causes of irritant contact dermatitis are highly alkaline soaps,
detergents, and cleaning products. Contact dermatitis of the scrotum may show a
variety of lesions varying from erythema, to papules, to vesicles or pustules,
but is always accompanied by itching. The scrotal skin is usually swollen,
occasionally edematous, painful, and red. Treatment is directed toward
discovery and elimination of the specific cause. Drug eruption is a form of
contact dermatitis that may occur on the scrotum and elsewhere on the body
after consumption of drugs to which the patient is allergic.
Allergic eczema or atopic
dermatitis often occurs together with other atopic diseases like hay fever,
asthma, and conjunctivitis. It is a familial and chronic disease and can appear
or disappear over time. Atopic dermatitis can often be confused with psoriasis.
It usually begins with superficial excoriation, localized edema, and exudation,
following which the lesion progresses to dry, thickened skin with scale
formation and a brownish hue. Marked pruritus or itching and pustule formation
are characteristic. The underlying cause remains obscure. Herpes simplex virus
type II (HSV-2, see Plate 2-21) is a form of genital herpes located on the
genitals that is more commonly observed on the penis than the scrotum.
Intertrigo or thrush is an
erythematous, inflammatory condition occurring where contiguous skin surfaces
are moist and warm. It is caused by the yeast Candida albicans that is
normally found on the skin. It is usually symmetrical on the scrotum and inner
surfaces of the thighs, with frequent involvement of the penis and buttocks.
Abrasions may lead to fissures and maceration, with the skin becoming
secondarily infected with bacteria. If the diagnosis is in doubt, a KOH test
can be performed to detect the candida yeast. A bacterial
culture can help diagnose a secondary bacterial infection. Intertrigo is
treated with antifungal creams such as clotrimazole and miconazole. Equally
important is to keep the skin folds as dry as possible.
Other rare skin lesions (not
illustrated) with a predilection for the scrotum are prurigo, which is a
general term for itchy eruptions of the scrotal skin, and lichen planus, an
inflammatory skin rash that forms scaly rings and plaques on the genitalia that
are characteristically
“violaceous” or purple
colored. Erythrasma of the genital region, a chronic infection by the bacteria Corynebacterium
minutissimum, appears as a brown, scaly, finely demarcated eruption that
produces no symptoms. Tinea versicolor, caused by the fungus Pityrosporum
ovale, is relatively common in adolescent and young adult males. It appears
as enlarging brown macules without inflammation or other symptoms and is treated with typical antifungal creams.
