Introduction
Pityriasis rubra pilaris (PRP) is a rare familial and acquired
papulosquamous disease. It is characterized by salmon-colored plaques
with islands of sparing and palmoplantar hyperkeratosis. This condition
can affect both adults and the pediatric population. 1Usually, it has a cephalocaudal progression, and the palms and soles
show a waxy yellow-orange keratoderma. 1 PRP’s
pathogenesis is not well understood. Still, there is evidence of
increased expression of the interleukin IL-12/IL-23 and IL-17 axes in
the affected skin. 2 There are various reported associations with PRP,
including infections, autoimmunity, drugs, and malignancies. Still, more
research is needed to understand these connections thoroughly.2 In familial cases, a specific gene mutation called
CARD14 has been identified. 2 The incidence and
prevalence of PRP are still unknown, but it is estimated to affect about
1 case per 400,000 of the population. 3 It tends to
occur most commonly in the first and fifth decades of life affecting
both men and women of all races equally. 4 The
histopathologic characteristics of PRP are variable, however, it
sometimes resembles psoriasis in its presentation. 5PRP is classified into six subgroups based on the age of onset, disease
severity, prognosis, and other associated characteristics.6 The subgroups: III (classical juvenile), IV
(circumscribed juvenile), and V (atypical juvenile) most commonly affect
children. 6 About 10%, 25%, and 5% of PRP patients,
respectively, are classified in these subtypes. 7
The course of the disease is variable; while some cases resolve
spontaneously, others may be very challenging to treat.1 There are no official recommendations, therefore
management is largely based on previous case reports. Topical
corticosteroids, retinoids, and vitamin D analogs are often used as
first-line therapy. 3,8 There is insufficient data
regarding pediatric patients. 9 Furthermore, there is
resistance to systemic therapy in children, however, it has been tried
for refractory cases in adults. 10 While oral
retinoids are considered the first choice as a systemic treatment, using
high-dose acitretin for a long time in children carries an increased
risk of side effects. 11 Currently, other systemic
therapies including immunosuppressants and biologics are used for the
treatment of juvenile PRP. 9 Here we present an
infantile case of type III PRP successfully treated with cyclosporine A
(CsA). Additionally, the use of CsA in juvenile-onset PRP is reviewed.