Discussion
CVG is a rare benign condition first described by Alibert in 1837
characterized by proliferation and hypertrophy of the skin of the scalp
or forehead. The affected skin then exhibits folds and furrows
resembling the cerebral cortex convolutions. Unna introduced the term
cutis verticis gyrata in 1907 [2].
This entity was afterward divided into different subtypes: a secondary
and a primary form, then the primary form was subdivided into primary
essential and non-essential. The primary essential form is the rarest
form, characterized by an isolated cutaneous involvement with no
associated pathology. It usually begins in adolescence and is more
common in men than in women. Typically, as seen in case 1, primary CVG
presents as symmetric scalp folds which usually extend anteroposteriorly
from the vertex to the occiput and transversally in the occipital
region. Terminal hair density is reduced on the folds, but not in the
furrows. The primary non-essential form has been described in
association with several neuropsychiatric pathologies like mental
retardation, epilepsy, microcephaly, schizophrenia, encephalopathy, and
other neurological malformations in addition to ophthalmic pathologies
such as blindness, strabismus, and congenital cataract, the latter being
the most frequent association. In primary non-essential CVG, the
associated conditions do not have a clear pathophysiological link with
the CVG.
Secondary CVG on the other hand is associated with conditions that may
be implicated in modifications of the trophicity of the skin. It is
slightly more common than the primary form. It can occur at any age
without gender predominance. It is associated with a variety of
underlying disorders. It may be caused by general diseases comprise as
liver affections, paraneoplastic syndromes, and pachydermoperiostosis or
also associated with inflammatory dermatoses most commonly psoriasis and
eczema [3]. Furthermore, various associated genetic conditions have
been described such as neurofibromatosis, Noonan, Turner, Klinefelter
and Ehlers–Danlos syndrome. It may also occur in association with
endocrine etiologies, as seen in case 3, such as diabetes mellitus,
myxedema, and the most described in the literature is acromegaly
[3]. Among iatrogenic causes, treatment with minoxidil or misuses of
anabolic substances were reported [4,5].
The pathophysiology of CVG remains unclear. On a structural level, it is
suggested that the folds are caused by connective tissue septa formation
between the skin and the galea. These septa prevent the expansion of the
skin which bulges into folds [6]. In the primary form, an endocrine
origin has been postulated as the disease usually manifests in
postpubertal males. Cases reported in the literature are sporadic
although some familial cases are described suggesting possible genetic
factors in primary CVG. The physiopathology in the secondary form
remains also unclear especially in general and inflammatory diseases.
However, in the physiopathology of endocrine etiology, trophic hormones
such as growth hormone (GH) and insulin growth factor 1 (IGF 1) were
incriminated to be responsible for skin modifications with collagen
thickening and hypertrophy of sebaceous glands.
When performed, histopathology of primary CVG shows normal skin.
Thickened connective tissue with hypertrophy or hyperplasia of adnexal
structures has also been described. Secondary CVG has variable histology
representing the underlying disease.
No treatment has proven its effectiveness in this entity. Abstention is
the rule in the primary form. In all cases, regular rigorous hygiene of
the skin folds and furrows is recommended to avoid maceration and
infection. If treatment is requested by the patient because of an
anesthetic complaint, medical and/or surgical treatment may be
suggested. Surgical treatment seems to be the best option with a
regularly reported efficacy. The undermining and relaxation incisions
alter the relationship between the skin and the deeper structures and so
result in the disappearance of the folds and furrows [7]. Medical
treatment includes isotretinoin or systemic steroids. No treatment can
prevent a recurrence.
In summary, CVG is a rare disease with mainly anesthetic impact. A
rigorous clinical examination with a minimal workup is however required
to eliminate a secondary or a primary non-essential form. If aesthetic
prejudice is important, surgical treatment can be suggested.