Pediatric emergency medicine trisk 341

Previously diagnosed patients with psoriasis may be receiving other
topical agents, including a variety of other more or less potent topical
steroids, tar derivatives, topical vitamin A derivatives (tazarotene), topical
vitamin D agents, emollients, and ultraviolet light. For severe cases, patients
may be receiving treatment with systemic immunomodulating agents,
including methotrexate, cyclosporine, acitretin, and a variety of biologic
modifiers that address specific targets in T-cell physiology.
Patients with pustular or erythrodermic flares of their psoriasis may
warrant admission in order to better control their disease, using more
intensive wet wrap therapies with topical steroids or initiation of systemic
immunomodulating therapies. Patients with extensive skin involvement and
skin barrier dysfunction may be at risk for hypothermia, skin infection,
bacteremia, and electrolyte abnormalities, and should be evaluated
accordingly. Older patients with psoriasis are also at higher risk for
cardiovascular disease and lipid abnormalities such as hypertriglyceridemia
and hypercholesterolemia.

Seborrheic Dermatitis
Seborrheic dermatitis is an inflammatory skin disorder characterized by
salmon-colored erythema and greasy scale concentrated on areas rich in
sebum production, including the scalp, eyebrows, ears, perinasal areas, beard
areas, and less commonly, the midchest, axillary, and inguinal areas ( Fig.
70.6 ). Despite the intensity of the rash, pruritus is often mild or nonexistent.


FIGURE 70.6 Infantile seborrheic dermatitis or “cradle cap.”

Seborrheic dermatitis condition is most commonly seen in infants,
adolescents, and adults. This is typically seen as an isolated phenomenon;
however, it may occur as an overlap with psoriasis (so-called
“sebopsoriasis”), atopic dermatitis, or may arise in association with

immunocompromised states, such as HIV, or Parkinson disease.
Scalp scaling is typically not associated with alopecia, which helps to
differentiate it from tinea capitis. The scalp involvement often shows a faint,
fine scaling in contrast to the more localized, thickly crusted cornflake-like
scale encountered in Langerhans cell histiocytosis (LCH). An inflammatory
reaction to local infection with Malassezia species has been demonstrated


and may explain the efficacy of antifungal treatment of seborrheic
dermatitis.
In cases where systemic findings are associated with seborrhea that is
new-onset, chronic, or particularly severe, workup should include evaluation
for HIV, immune deficiency, or LCH.
Treatment depends on the sites of involvement. For scalp involvement, an
anti-inflammatory antifungal shampoo is appropriate: selenium sulfide,
ketoconazole, or ciclopirox shampoos used daily for a week, and then
maintained twice weekly is often sufficient. The facial involvement can be
managed with once- or twice-daily use of a topical anti-inflammatory
antifungal creams such as clotrimazole or ketoconazole cream prn.
Occasionally, for more severe flares, brief courses of low-potency topical
steroid (hydrocortisone 1% or 2.5%) or calcineurin inhibitor (pimecrolimus
cream or tacrolimus ointment) can be applied twice daily for up to a week at
a time on an as-needed basis. As this tends to be a chronic, relapsing
condition, advising appropriate follow-up is important.

Pityriasis rosea
PR is a self-limited inflammatory skin disorder characterized by an initial
larger herald patch or plaque, followed by the eruption of multiple smaller
oval papules and plaques concentrated on the neck and torso areas.
Individual lesions often show a collarette of scale ( Fig. 70.7 ) and typically

follow lines of skin tension in a so-called “fir tree” or “Christmas tree”
pattern. The condition is most commonly seen among adolescents and
adults. Younger patients and those with darker skin may show atypical
features with greater involvement of palms and soles, or an inverse pattern
with concentrated areas in the intertriginous folds.


FIGURE 70.7 Pityriasis rosea with characteristic trailing edge scale within these oval
papules and plaques.

PR is thought to be a reaction pattern to a preceding viral or other
infectious process. Reactivation of latent human herpesvirus 6 or 7 (HHV
6,7) has been postulated as one potential mechanism. Given its clinical
resemblance to secondary syphilis, adolescents and adults or those with risk
factors for syphilis should be screened appropriately. Chronic cases of what
looks like PR lasting longer than the typical 4 to 8 weeks should be
evaluated for pityriasis lichenoides.
Since the condition is self-limited and often asymptomatic, reassurance
and anticipatory guidance may be sufficient. For those who are symptomatic
or desire a more rapid remission, treatment with oral acyclovir (ostensibly to
treat HHV 6,7) or oral erythromycin (presumably for its anti-inflammatory
properties) for 10 to 14 days may hasten resolution of the condition.

Pityriasis rubra pilaris
PRP is a rare chronic inflammatory skin condition typified by salmoncolored, orange-red follicular papules and larger plaques accompanied by