Clinical image:
A 56 years old female patient with a 5-year history of plaque psoriasis
treated with topical corticostreoids and phototherapy was admitted to
the Department of Dermatology for a generalized rush which appeared
after she reduced the dose of an oral treatment based on 60 mg of
prednisone. Dermatological examination revealed well-demarcated, large,
annular erythematous and squamous lesions (Figure1), with peripheral
micro- pustules. The polycyclic plaques was paler centrally surrounded
by raised ring, confluent numerous pustules with trailing scale (Figure
2). The patient had no systemic symptoms or fever. Laboratory tests
revealed a biological inflammatory syndrome with a normal calcemia and a
sterile pustule at the bacterial sampling. Several diagnostics have been
suggested: acute generalized exanthematous pustulosis, annular pustular
psoriasis and subcorneal pustular dermatosis.
Histopathological examination revealed a subcorneal spongiform
pustule, acanthosis with hyperkeratosis and parakeratosis. In the
dermis, there was a mononuclear cells and neutrophils infiltrate
(Figure3).
The diagnosis of generelized annular pustular psoriasis (Millian
Katchoura type) was retained because of the personal history of
psoriasis, the evocative clinical aspect, and the histological
findings. The patient was treated with acitretin 10 mg/ kg/ day with a
total regression of lesions.
Annular pustular psoriasis, described by Milian and Katchoura in 1933,
is a rare form of pustular psoriasis. The pustular psoriasis may be
induced or worsen by a number of factors primarily drugs such as
lithium, beta blockers, terbinafine, biotherapy, hydroxychloroquine and
a rapid taper of oral corticosteroids (1, 2). In order to avoid serious
complications such as the occurrence of pustular forms of psoriasis,
systemic corticosteroids should be prescribed with great caution to the
patients.
Legends:
Figure1: Annular erythematous and squamous lesions
Figure2: Poly-cyclic pustular and papular lesions with trailing scale
Figure 3: subcorneal spongiform pustule, a mononuclear and neutrophils
cell infiltrate the dermis (Hematoxylin and eosin x200)
Reference :
Westphal DC, Schettini APM, Souza PP, Castiel J, Chirano CA, Santos M.
Generalized pustular psoriasis induced by systemic steroid dose
reduction. An Bras Dermatol. 2016;91(5):664-6.
Du-Thanh A, Girard C, Pageaux GP, Guillot B, Dereure O.
Sorafenib-induced annular pustular psoriasis (Milian-Katchoura type).
EJD, vol. 23, n◦ 6, November-December 2013