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Many generalized dermatologic conditions can affect the face and
scalp. This chapter discusses the acneiform eruptions, seborrheic
dermatitis, erysipelas and facial cellulites, impetigo, herpes zoster,
herpes simplex, tinea capitis and barbae, head lice, allergic contact
dermatitis, and photosensitivity/sunburn.
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The acneiform eruptions include acne vulgaris, pyoderma faciale,
dissecting cellulitis of the scalp, and acne keloidalis nuchae. Pathophysiology
of these disorders is similar. Sebum secretion is increased within
the sebaceous follicle by androgen stimulation. Keratin accumulates
in the hair follicle as well as sebum. Host inflammation occurs,
and the bacteria Propionibacterium acnes (gram-positive
rods) proliferate and accumulate, intensifying inflammation. At
this stage, an inflammatory papule or pustule occurs. An
influx of neutrophils and T-helper cells occurs during inflammation.
In addition, marked inflammation can cause a nodule and cyst, and
scarring can result. Pathophysiology of cutaneous scarring includes
follicle blockage, rupture with keratin dispersion, and neutrophilic
and granulomatous response.
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Acne vulgaris, although commonly afflicting young
patients, can occur in adult patients as well. White males tend
to have the more severe form of nodulocystic acne. Other predisposing
conditions include polycystic ovarian syndrome and hypercortisolism
such as congenital adrenal hyperplasia. Acne fulminans is
the most severe form of nodulocystic acne and may prompt patients
to seek emergency medical attention. It usually affects
males between the ages of 13 and 16 years. Most patients
have a history of acne before onset. Some individuals with severe
acne who have started isotretinoin without systemic corticosteroids
are predisposed to developing acne fulminans. Clinical
features of acne fulminans include acute onset of suppurative cysts
and nodules with ulcerations and hemorrhagic crusting (Figure
246-1). Ulcerating lesions can lead to severe scarring. Acne
fulminans commonly affects the chest and back as well. Systemic
symptoms also occur and include osteolytic bone lesions of the clavicle
and sternum, fever, arthralgias, myalgias, and hepatosplenomegaly.
Diagnosis is clinical. Acute treatment includes administration of
40 to 60 milligrams of prednisone once a day. If the patient is
on isotretinoin, it should be continued in conjunction with the
corticosteroids. Isotretinoin should not be given in the acute care
setting. Referral to a dermatologist is appropriate. In
that setting, topical, intralesional, oral corticosteroids, and/or oral
isotretinoin with or without oral antibiotics can be initiated.
Isotretinoin has potential severe teratogenic effects in pregnant
women and requires patient registration, and online documentation
of pregnancy test results.
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Pyoderma faciale, or rosacea
fulminans, is an inflammatory cystic acneiform eruption on the central
face of young women. The eruption may occur without a history of
rosacea. Inflamed papules and pustules are present on the centrofacial
region and can coalesce into large plaques. Diagnosis is clinical.
Severe scarring can occur without treatment. ...