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 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 to 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