To the Editor:
Pustular psoriasis is a rare form of psoriasis characterized by an eruption of sterile
pustules. It can be divided into both generalized and localized forms1. Some authors
consider a separate variant of generalized psoriasis, well described by Lapière, as
recurrent circinate erythematous psoriasis. It presents with erythematous, annular
or polycyclic lesions, and an eruption of small sterile pustules and fine desquamation.
The patches extend from the center and resolve within some weeks, leaving scales and
changes in pigmentation and pigmentary changes. Frequent relapses are described in
the bordering areas2,3.
In this study, we report the case of a woman affected by generalized annular pustular
(Lapière) psoriasis. This patient had previously been treated with conventional therapeutics,
and demonstrated a significant improvement after treatment with etanercept. This 70-year-old
Caucasian woman, described in our report, has a 35-year history of psoriasis. Physical
examination revealed the presence of small erythematous papules, centered by a pustule,
a few millimeters in diameter (Fig. 1). Histological examination showed Kogoj-Lapière
spongiform multilocular typical pustules (an epidermal pustule formed by infiltration
of neutrophils into necrotic areas of the epidermis, where the cell walls form a swampy
network), features compatible with the clinical diagnosis of Lapière psoriasis. The
patient had previously been treated with other topical and systemic drugs (colchicine,
acitretin, ciclosporin, methotrexate) and ultraviolet B narrow band phototherapy,
with partial and temporary benefits, side effects, and frequent relapses. Differential
diagnosis of our case included other generalized pustular psoriasis: acute generalized
exanthematous pustolosis (AGEP) was perhaps the most important differential diagnosis.
AGEP, which occurs as an acute, spontaneously healling reaction to drugs (usually
antibiotics), was excluded on the basis of the absence of vasculitis associated with
spongiform pustules and based on the presence of psoriatic anamnesis. Lapière psoriasis
can be differentiated from pustular lesions caused by prolonged application of topical
steroids or tar ointments on the periphery of pre-existent psoriatic plaques. Unlike
the Von Zumbusch generalized form, the general state of health is not compromised.
The patient was treated with 50 mg of etanercept twice weekly subcutaneously for three
months. There was an extremely rapid response, noticeable from the second day, with
complete clearance of the pustular eruption at the end of the first week. At week
12 of etanercept treatment, complete clearance of cutaneous lesion was achieved (Fig.
2), including erythema and scaling, with no significant side effects reported, concomitant
infections, decreased blood granulocytes or other laboratory changes. Maintenance
treatment with 50 mg of etanercept once a week subcutaneously was continued for another
three months. No relapse was noted at week 35.
There are no universally accepted guidelines for management of Lapière psoriasis;
no clinical trials have been conducted and no single agent has been approved for this
indication. Only case reports or short series of patients have been published on the
off-label use of biologic drugs for pustular psoriasis4,5. In contrast, de novo paradoxical
pustular flares induced by anti-tumor necrosis factor (anti-TNF-α) therapy have been
described6.
Etanercept is a soluble recombinant human tumor necrosis factor α (TNF-α) receptor
that acts as a competitive inhibitor of TNF-α by binding to and inactivating endogenous
TNF-α, thereby preventing its interactions with cell surface receptors7. Based on
our experience, etanercept may be an effective therapeutic option in the treatment
of Lapière psoriasis. In fact, in our patient, etanercept demonstrated a high efficacy
with a rapid and significant clinical response associated with an excellent safety
profile. The rapid clearance, the good maintenance of efficacy and the excellent tolerability
suggest a role for etanercept in the management of Lapière psoriasis, especially in
elderly patients with typical pathologies. Specifically, this may apply if other treatment
modalities are contraindicated or proven to be ineffective.