A key clinical message:
Harlequin syndrome corresponds to unilateral dysfunction of sympathetic
system, characterized by flush and unilateral hyperhidrosis associated
with hypo or anhidrosis and paleness of the opposite side. It is,
usually, idiopathic. Rarely, it may be associated with compressive
organic processes, iatrogenic causes and general diseases. It is a real
therapeutic challenge.
The Harlequin syndrome, was described for the first time by Lance et al
in 1988, as an uncommon disorder of the sympathetic nervous system
[1]. It is characterized by unilateral diminished sweating and heat-
or exercised-induced facial flushing [1]. We present the cases of
two patients with this rare syndrome, including a review of the
literature.
Patient N°1:
A 27-year-old man, with a medical history of migraine, consulted for
flushing and an excessive sweating on the left side of his face evolving
for few months. This contrasted with anhidrosis and normal appearance of
the right side of his face (Fig. 1). These skin changes were triggered
by physical exercise and disappeared spontaneously at rest.
Dermatological examination at rest revealed no abnormalities. Findings
of physical and neurological examinations were normal. Routine
laboratory studies and carotid artery ultrasonography yielded normal
results. Thus, the diagnosis of idiopathic Harlequin was established.
Patient N°2:
A 22-year-old man, with no specific medical history, presented with an
excessive sweating and flushing on the left side of his body including
his face evolving by relapses for 2 years. No triggering factor was
found. On examination at rest, we noted an asymmetric flushing and
hyperhidrosis limited to the left side of his face, neck and upper trunk
(Fig. 2). The neurological examination revealed a left ptosis, a
pupillary asymmetry with a tendency to miosis, leading to an incomplete
Claude Bernard Horner syndrome (CBH). Bilateral pupillary paresis was
also noted. The blood pressure was within the normal range. Routine
laboratory studies, carotid artery ultrasonography, magnetic resonance
of angiography of the head ruled out secondary causes. So, we evoked the
diagnosis of idiopathic Harlequin syndrome associated with CBH.
To the best of our knowledge, only almost one hundred cases have been
reported through literature [2]. This phenomenon corresponds to
unilateral dysfunction of the sympathetic system [2, 3]. It is
characterized by flush with unilateral hyperhidrosis associated with
hypo or anhidrosis and paleness of the opposite side [1-3]. This was
explained by a compensatory mechanism on the unaffected sympathetic
innervated side [1-3]. Arms and trunk may be affected, as well as
our patient [4, 5]. Some triggering factors were reported, such as:
heat, emotions or physical efforts, which are the usual stimuli of the
sympathetic nervous system [1-3]. This phenomenon was reported in
association with dysautonomic syndromes such as CBH, as illustrated in
our second patient [3]. The association between Harlequin syndrome
and migraine was also described, as well as our first patient [1,
2]. In most cases, Harlequin syndrome is idiopathic [1-3].
However, rarely this syndrome may be secondary to compressive organic
processes of T2 and T3 sympathetic trunks such as medullary astrocytoma,
mediastinal neuroma, pulmonary neoplasia of the apex, or carotid
dissection [1-8]. Iatrogenic causes are increasingly described in
particular jugular venous catheterization, thoracic sympathectomy, or
after resection of anterior mediastinal tumor [1-8]. In addition,
some general diseases may also cause Harlequin syndrome, including
Barred Guillain syndrome, diabetic neuropathy, or multiple sclerosis
[1-8]. The diagnostic approach seeking systematic secondary
etiologies of Harlequin syndrome requires a rigorous interrogation. It
is recommended to study the carotid cervical arterial by carotid artery
ultrasonography network and even magnetic resonance of angiography of
the head [2, 4]. The phenomenon of Harlequin is most common in women
patients at the third decade leading to an important social
embarrassment requiring treatment [2]. Apart from the secondary
cases where the compressive origin can be surgically removed, the
therapeutic possibilities are very few; limited to contralateral
sympathectomy, repeated block of the stellate ganglion and botulinum
toxin [9, 10].
Through our case report, we would like to make clinician aware of this
rare syndrome and its management options in order to ameliorate quality
of life among patients suffering from Harlequin syndrome.
Acknowledgments: None
Conflict of interest: None
Keywords: Harlequin syndrome, flush, dysautonomic syndrome
Funding : This research did not receive any specific grant from
funding agencies in the public, commercial, or not-for-profit sectors.