Brief communication

Leukocytoclastic vasculitis in urticaria induced by sun exposure

Giuseppe Stinco1, Luca Di Gaetano1, Claudio Rizzi2, Pasquale Patrone1

1Department of Clinical and Experimental Pathology and Medicine, Institute of Dermatology, University of Udine, Udine, Italy, and 2Institute of

Pathology, A.S.S. ‘Bassa Friulana’, Pamanova (Udine), Italy

Background: Solar urticaria manifests itself immedi-

ately after solar or artificial light exposure and dis-

appears a little later. Histopathologic findings of solar

urticaria are essentially identical to those of classic

urticaria.

Case report: We report a 41-year-old man who devel-

oped urticarial lesions some hours after sunlight ex-

posure, which resolved after approximately 1 week.

Histologic examination of the lesions evidenced a

leukocytoclastic vasculitis.

Conclusion: In a literature review we found one case

of solar urticaria with histologic aspects of leukocyto-

clastic vasculitis.

Key words: leukocytoclastic vasculitis; phototest solar

urticaria.

Solar urticaria is a relatively rare form of physical

urticaria. It manifests immediately after solar or

artificial light exposure and disappears after some

minutes or hours. The triggering radiations are UVA

(320–400 nm) and visible light (400–600 nm), less fre-

quently the UVB (280–320 nm) and very rarely the

infrared (4600 nm). The clinical and histologic fea-

tures are similar to those of common urticaria (1, 2).

Vasculitic urticaria is characterized by wheals of

small-medium dimensions that persist for more days,

can be more painful than pruritic, and sometimes can

revert, leaving purpuric lesions. The biopsy of vascu-

litic urticaria reveals a leukocytoclastic vasculitis. The

cutaneous lesions may be accompanied by fever,

arthralgias, abdominal and thoracic pain, glomerulo-

nephritis and uveitis (3). Recently, we have observed a

case of solar urticaria with the histologic character-

istics of leukocytoclastic vasculitis. In the literature,

only one similar case is described (4).

Case reportA 41-year-old man presented with wheals of approxi-

mately 1 cm diameter, at times confluent, after sun-

light exposure, with the first episode occurring 9 years

ago. The lesions initially appeared only on the fore-

arms; they were non-pruritic and non-painful, devel-

oped some hours after sun exposure of large body

surface area and disappeared approximately after 1

week. The single exposure of the face and hands was

never sufficient to induce the appearance of the

wheals. The manifestations appeared every year in

the summer months with the same characteristics and,

in the last 3 years, they also extended to the superior

and inferior limbs (Fig. 1). The patient is otherwise in

good health and does not take any medication. There

was no family history of urticaria.

The laboratory studies turned out to be normal;

there were no alterations in the inflammatory indices,

autoantibodies and porphyrin assay.

Phototests were conducted. We used the unit of

phototherapy Daavlin Spectras

724-sp UVA as a

source of UVA radiations (320–400 nm), the unit of

phototherapy Daavlin Spectras

724-sp UVB as a

source of UVB radiations (280–320 nm). As a source

of visible light we used a slide projector. Irradiance of

UV sources was measured by a photometer (Wald-

mann’s UV-meter). Physical measurements of the

irradiance and spectrum of the slide projector lamp

were not available. To determine MED-UVA the

patient was exposed to 5–7.5–10 J/cm2 and no reaction

was observed. To determine MED-UVB, we used 30–

90–150–210–300mJ/cm2 and after 24 h the minimal

erythema dose was 90mJ/cm2.

In the attempt to determine the minimum urticarial

dose (MUD), we irradiated areas of 5 � 5 cm with 10

and 20mJ/cm2 of UVB, 10 and 20 J/cm2 of UVA and

with visible light for 30min. The test was read im-

mediately, after 6 and 24 h, and it was negative.

Subsequently, the patient was exposed to irradiation

Photodermatol Photoimmunol Photomed 2007; 23: 39–41Blackwell Munksgaard

r 2007 The Authors.Journal compilationr 2007 Blackwell Munksgaard

39

of the whole body surface with 10mJ/cm2 of UVB and

10 J/cm2 of UVA, with no appearance of wheals. A

provocative test with natural sunlight was performed.

Only a 30-min exposure on a sunny day produced a

positive reaction in our patient, determining the pre-

sence of wheals in the superior and inferior limbs.

The other physical tests for urticaria were negative.

Histologic examination of a wheal in the thigh area

evidenced leukocytoclastic infiltrate within and

around the walls of blood vessels at the superficial

and deep level of the dermis (Fig. 2a and b). Inside the

vessel wall, numerous neutrophils and lymphocytes,

some plasma cells and fragments of nuclei from

neutrophils (nuclear dust) were recognized (Fig. 2c).

The endothelial cells appeared swollen. This picture

was compatible therefore with leukocytoclastic vascu-

litis.

In the past the patient had used hydroxyzine (25mg

twice a day), cetirizine (10mg daily) and loratadine

(10mg daily) without benefit. A combination of lor-

atadine (10mg daily) and ranitidine (150mg twice a

day) did not improve the clinical course of the disease.

He was also not compliant with the use of sunscreens.

On two occasions, systemic corticosteroids, oral pre-

dnisone (50mg daily) or deflazacort (60mg daily) did

not modify the duration of the manifestations.

DiscussionSome cases of solar urticaria have been described in

the literature, where the wheals appeared after a

longer period of latency and their duration was longer,

but there has never been a histologic documentation

(1). In only one case the histologic examination

revealed a leukocytoclastic vasculitis. It was a case

of a 35-year-old woman who, similar to our patient,

presented urticarial lesions that appeared 1–4 h after

irradiation with sunlight or artificial UV radiations

and lasted several days before resolving. The patient

used sunscreens to control the manifestations (4).

In our case, the wheals do not develop after the

exposure of the face and hands, but only if the patient

exposes larger areas of the body. The phototests we

performed were negative and the complete irradiation

of the entire body surface was not sufficient to elicit

the reaction. Only a provocative test with natural

sunlight produced a positive reaction. Consequently

Fig. 1. Wheals in the thigh area appeared 3 h aftersunlight exposure at the seaside.

Fig. 2. Perivascular infiltrate at the superficial anddeep level of dermis (hematoxylin–eosin, originalmagnification � 10) (a); leukocytoclastic infiltratewithin and around wall of a blood vessel, which showsswelling of endothelial cells (hematoxylin–eosin, ori-ginal magnification � 20) (b); nuclear dust secondaryto degeneration of neutrophils (hematoxylin–eosin,original magnification � 40) (c).

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Stinco et al.

it was not possible to establish the wavelength of the

radiation which could induce the urticaria. However,

the inability to reproduce the manifestations of the

solar urticaria by using phototests was already known

in the literature (5). It depends mainly on the fact that

the tests are conducted with exposures of few minutes

on small body areas, while the wheals appear after a

longer sunlight exposure on large body surface areas.

We do not know exactly whether the wheals appear

after a long and massive exposure to light or whether

there is a local factor that determines the development

of the wheals localized on the limbs and spares the

other photo-exposed regions.

The most difficult differential diagnosis is polymor-

phous light eruption (PLE). We consider that our

patient did not have a PLE because he showed only a

monomorphic eruption of wheals localized only on

the limbs, while the most frequent locations of this

photodermatosis, the V area and the neck, were not

involved. Moreover, in the literature leukocytoclastic

vasculitis has never been described in PLE, whose

histologic features consist of spongiosis, acanthosis,

parakeratosis and perivascular round cell infiltrate of

the dermis.

Considering the rarity of solar urticaria, the treat-

ment of choice is not known. The patient used anti-H1

antihistamines alone and in association with anti-H2,

but they were not effective in prophylaxis and did not

modify the evolution of the wheals. Not even the

usage of systemic corticosteroids influenced the clin-

ical outcome. The patient was noncompliant in using

sunscreens so we do not have any data on their

protective capacity, even though we assume their

effectiveness if applied in a constant and careful way.

A therapeutic approach could be the use of photo-

therapy (PUVA), or the prescription of colchicine or

systemic photoprotectors such as hydroxychloro-

quine. Considering the random appearance of the

lesions and their mild clinical course, we think that a

preventive measure of avoiding solar exposure and the

follow-up of the patient are the preferred course of

treatment.

References1. Beattie PE, Dawe RS, Ibbotson SH, Ferguson J. Characteristics

and prognosis of idiopathic solar urticaria. Arch Dermatol

2003; 139: 1149–1154.2. Horio T. Solar urticaria – idiopathic? Photodermatol Photo-

immunol Photomed 2003; 19: 147–154.

3. Iannello S, Asmundo GO, Cataliotti A, et al. Urticarial vascu-

litis syndrome. A case report and review of the literature.Minerva Med 1997; 88: 459–467.

4. Armstrong RB, Horan DB, Silvers DN. Leukocytoclastic vas-

culitis in urticaria induced by ultraviolet irradiation. Arch

Dermatol 1985; 121: 1145–1148.5. Ryckaert S, Roelandts R. Solar urticaria. A report of 25 cases and

difficulties in phototesting. Arch Dermatol 1998; 134: 71–74.

Accepted for publication 19 October 2006

Corresponding author:

Giuseppe Stinco

Institute of Dermatology, University of Udine,

Ospedale ‘San Michele’

piazza Rodolone 1

33013 Gemona del Friuli (Udine), Italy

Tel: 139-0432-989-78

Fax: 139-0432-989-209

e-mail: giuseppe.stinco@uniud.it

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Leukocytoclastic vasculitis in urticaria