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FIGURE 70.10 Scaly hypopigmented patches of pityriasis lichenoides chronica.

While the diagnosis can sometimes be made on clinical grounds,
consultation with a dermatologist and possible skin biopsy is generally
necessary to differentiate it from other conditions. Since the condition rarely


represents a precursor to cutaneous T-cell lymphoma, periodic longer-term
outpatient monitoring is advised.
Treatment for the condition typically involves an initial trial of macrolide
derivatives such as erythromycin, and recalcitrant cases may be treated with
ultraviolet light phototherapy. More severe cases, including those with
FUMH, typically require systemic immunosuppressive therapy with agents
such as methotrexate. Breaks from therapy can often be taken during the
summer months when disease activity wanes from natural sunlight exposure.
Long term, the condition remits spontaneously over a period of several
years.

Lichen nitidus
Lichen nitidus is a benign, self-limited condition characterized by crops of
small (1 to 2 mm), discrete flat-topped off-white papules scattered over the
torso and extremities ( Fig. 70.11 ), but which can involve the face and
genitalia as well. Lesions often show characteristic groups of papules, with
some in a linear configuration demonstrating the phenomenon of
koebnerization at sites of minor trauma. In contrast to follicular eczema,
which is often pruritic, the skin in lichen nitidus is usually asymptomatic.
Treatment typically involves watchful waiting and reassurance, although
some patients may respond to topical corticosteroids or calcineurin inhibitors
such as pimecrolimus cream or tacrolimus ointment.

Lichen planus

Lichen planus is often easily recognized by its intensely pruritic, purplish,
often polygonal papules and plaques ( Fig. 70.12 ). The condition can occur
anywhere, but is usually seen involving the extremities. Areas may show
koebnerization, with lesions appearing at sites of minor skin trauma.
Affected patients should be asked about and examined for oral or genital
involvement, which may or may not be symptomatic at these sites. On the
mucous membranes, the condition has a lacy white appearance.


FIGURE 70.11 Lichen nitidus.

FIGURE 70.12 Lichen planus.

In adults, the condition may be associated with underlying hepatitis C
infection, although children who present with lichen planus are generally


otherwise healthy. Nonetheless, it is advisable to ask about any risk factors
or family history of hepatitis C.
Since patients with lichen planus are usually uncomfortably itchy,
treatment is recommended. For the body affected areas of skin, topical
therapy using moderate potency topical steroids such as fluocinolone
0.025% or triamcinolone 0.1% twice daily is suggested for 2 to 4 weeks to
moderate the pruritus. For more widespread involvement seen in generalized
lichen planus, or those with more severe oral or genital involvement which
may be sore or painful, a course of oral corticosteroid therapy or other
immunosuppressants may be necessary. Since lichen planus is a chronic
condition, consultation with a dermatologist is recommended.

Lichen striatus

Lichen striatus is a papulosquamous condition that most commonly presents
as a single linear, scaly, and thickened plaque consisting of smaller pink
papules, typically on an extremity. The lesion is often discontinuous and
follows the curvilinear lines of Blaschko. After several months, the papular
component fades, leaving behind hypopigmented areas in the same linear
configuration ( Fig. 70.13 ). Lichen striatus is most often seen in schoolaged children. In contrast, inflammatory linear verrucous epidermal nevi
(ILVEN) which can look similar, are often earlier in onset, arising in infancy,
and may be more widespread ( Fig. 70.14 ).

FIGURE 70.13 Lichen striatus.