Article Type : Research Article
Authors : Talwar R, Talwar A and Narad R
Keywords : Cerrucous psoriasis; Cutaneous horn; Verrucous carcinoma; Arsenical keratosis; Verruca vulgaris
A cutaneous horn is a yellow or
white-colored conical projection made up of complex keratin that arises from
the surface of the skin. It is usually diagnosed clinically but requires
histologic examination to rule out malignancy or determine the underlying
lesion. Psoriasis is a common inflammatory disease with a range of clinical
presentations and a chronic relapsing course. There have been few reports of
verrucous psoriasis, which is distinguished by its warty appearance and
characteristic histology. We report a case of a 45-year-old male who presented
with multiple cutaneous horns overlying the previous psoriatic plaques on
unique locations, dorsa of hands, elbows, lumbosacral area and dorsa of feet.
Post-excision biopsy revealed a diagnosis of a verrucous psoriasis-associated
cutaneous horn.
Verrucous psoriasis (VP)
is a rare variant of psoriasis characterized by hyperkeratotic, papillomatous
plaques that clinically resemble verrucous carcinoma (VC) in lesion appearance
and distribution. It is amenable to medical treatments. A cutaneous horn, less
commonly described as cornu cutaneum or Devil's horn, is a conical, protruding,
hyperkeratotic growth, sometimes large enough to resemble an animal horn. Due
to their clinical ambiguity and potential malignancy, these lesions must
undergo biopsy from the base for histopathological analysis. Only then can
subsequent, appropriate treatment be initiated. We report a case of a rare
clinical variant, verrucous psoriasis, presenting as multiple cutaneous horns.
Verrucous psoriasis (VP)
is a rare variant of psoriasis with wart-like changes clinically and
histologically. It is characterized by symmetric hypertrophic verrucous plaques
that may have an erythematous base and involve the legs, arms, trunk, and
dorsal aspect of the hands [1]. Cutaneous horn is a conical markedly
hyperkeratotic excrescence or overgrowth of epidermis that is usually seen in
squamous cell carcinoma, basal cell epithelioma, nevoid conditions, wart, and
keratoacanthoma. They are usually solitary and frequently associated with
malignant change of the underlying epidermis [2]. To our best knowledge, there
have been just 2 case reports of verrucous psoriasis presenting as multiple
cutaneous horns to date.
Histologically, VP is
characterised by overlapping features of verruca vulgaris and psoriasis. A
large histopathologic study of 12 cases of VP reported regular psoriasiform
epidermal hyperplasia with acanthosis, hyperkeratosis, and neutrophil
collections in the stratum corneum (Munro microabscesses) or stratum spinosum
(spongiform pustules of Kogoj) [1]. In addition, they reported papillomatosis
with bowing of the peripheral rete ridges toward the centre of the lesion (buttressing).
These findings are highly suggestive of verrucous psoriasis. These changes were
noted in our case too. Hypergranulosis and koilocytic change, typical of
verruca vulgaris, are usually not observed.
The etiology of this
entity is unknown. Others have reported repeated trauma as contributing to the
pathogenesis [3]. In our patient, there was no history of trauma but intake of
a combination of homeopathic drugs for a long duration may have precipitated his
condition.
Verrucous psoriasis can
be recalcitrant to therapy. Although there are no studies addressing treatment
modalities, several recommendations can be derived from individual case
reports. The use of topical therapies, including topical corticosteroids,
keratolytic agents and calcipotriene, provide only minimal improvement when
used as monotherapy [3]. There have been successful reports of management of VP
with systemic therapies like methotrexate and acitretin [4,5]. Of particular
significance was a case report using a combination of acitretin with
methotrexate for successful clearance of a case of VP [5]. In view of the
extremely hyperkeratotic nature of the lesions and their high number in our
patient, we chose to go with this combination. This combination has
traditionally been avoided because of the risk for hepatotoxicity. However, a
case series has demonstrated a moderate safety profile with concurrent use of
these drugs in treatment-resistant psoriasis [6]. Our patient showed a
tremendous clinical response with this combination with most lesions flattening
out over a 6 month period. No side effects have been noted till date and the
patient continues to be in treatment with regular follow up.
A 45 year old man presented to us:
Differential Diagnoses
Investigations
Routine investigations: These included complete hemogram, blood sugar, uric
acid, and thyroid function tests, all of which were within normal limits.
Arsenic level estimation: This was done from nail and hair samples and the
report was normal.
Vascular/Doppler Ultrasound: Showed marked irregular-thickening of the
epidermis with a superficial exophytic polypoidal outgrowth demonstrating no
significant colour-flow or any sizeable enlarged, tortuous veins or feeding
arteries. Dermis-epidermis junction appears relatively-preserved.
Skin Biopsy: A wide excision biopsy was done from two different
sites. The HPE showed marked psoriasiform epidermal hyperplasia with acanthosis,
hyperkeratosis, parakeratosis and papillomatosis (Figure 6). In addition,
inward bowing of the peripheral rete ridges toward the centre of the lesion
(buttressing) was noted. Collections of neutrophils within the stratum corneum
and stratum spinosum was also noted (Figure 7). Dermis showed a superficial
perivascular, lymphocyte-predominant inflammatory infiltrate. No dysplasia was
noted.
Verrucous Psoriasis
Treatment
The prior homeopathic treatment was stopped. The patient was started on a combination of oral weekly methotrexate with acitretin 25mg daily in accordance with a case report of successful management of VP with this combination [5]. Topically, the patient was advised 12% salicylic acid cream to be applied over the most hypertrophic areas together with emollient application multiple times in a day.
The patient showed
significant improvement 6 weeks into the treatment. The thick horns started to
flatten out and became softer on palpation. By 3 months, the horns had shrunk
to half their original size and the scaly psoriatic plaques had disappeared
everywhere except the back. By 6 months, most of the horns had regressed (Figures
8-10). Only the scaly psoriatic plaques at the back remained (Figure 11). The
patient continues to be under treatment and regular follow up.