Page 153 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-68 Rashes
ROSACEA

Rosacea is an extremely common chronic dermatosis.
This inflammatory dermatosis is associated with many
triggers or initiating factors that can cause a flare of
the inflammatory response. There are various forms,
including erythematotelangiectatic, papular pustular,
ocular, and phymatous varieties and rosacea fulminans.
The erythematotelangiectatic form is the most Rhinophyma
common. Rosacea fulminans is the least common but
by far the most severe form.
Clinical Findings: Rosacea is most often seen in
Caucasians, especially those of northern European
heritage. There is a slight overall female predominance.
The phymatous form occurs almost exclusively in men.
The peak age at onset has been estimated to be in the
third to fourth decades of life. Most patients start with
a subtle redness to their cheeks and nose. The forehead
and ears are less commonly affected. Most patients
notice a trigger or inciting factor that makes their skin
flush. Triggers include alcohol, hot spicy foods, hot
liquids (e.g., coffee, tea), and exposure to extremes of
temperature. Patients can have any, all, or none of the
typical triggers. On exposure to a trigger, patients often
experience a warmth to the skin and flushing of the
areas involved by rosacea.
The diagnosis is typically straightforward and is made
on clinical grounds; however, the differential diagnosis
in some cases can include other causes of flushing and
lupus erythematosus. The butterfly rash of lupus erythe-
matosus can look very similar, and occasionally a skin
biopsy is required to help differentiate the two. This is
unusual, because the systemic manifestations of lupus
are not seen in rosacea. This scenario is most common
when a patient with known lupus erythematous presents Erythematotelangiectatic rosacea
with a facial rash and the underlying lupus must be dif-
ferentiated from co-existing rosacea as the cause.
Other common forms of rosacea are the papular
pustular and ocular forms. Patients with the papular
pustular form typically start off with the erythematotel-
angiectatic form and progress to this form over time.
Not every case of erthematotelangiectatic rosacea pro-
gresses, however. Patients begin to develop crops of
inflammatory papules and pustules, predominantly on
the nose and cheeks. The forehead and chin can also be
involved. The appearance can be hard to differentiate
from acne, but these patients typically have triggers,
some flushing, and a later age at onset. The back and
chest are not involved by rosacea. Patients with ocular
rosacea present with conjunctivitis and blepharitis.
These are manifested clinically by redness of the con-
junctiva and a feeling of “sand” in one’s eye. It can be
a solitary finding, but it is more commonly seen in
conjunction with skin disease.
Phymatous rosacea is caused by massive overgrowth
of sebaceous glands with edema and enlargement of the
structures affected. This is most common on the nose
of men, in which cases it is called rhinophyma. The
appearance of the nose can become distorted, leading Rosacea Fulminans
to a red, edematous, bulbous deformity with accentu-
ated follicular openings.
Rosacea fulminans is a rare variant that can have an
acute onset of severe papules, pustules, nodules, and lymphocytic infiltrate may surround adnexal structures. sulfacetamide, oral tetracyclines) has long been the
cyst formation. Papular rosacea shows perifollicular abscesses. An inter- mainstay of therapy. Topical azelaic acid has also been
Pathogenesis: The etiology of rosacea is unknown. esting finding with unknown relevance is that of multiple helpful. Avoidance of triggers is helpful in some indi-
Subtypes are most likely a heterogeneous group of demodex mites within the hair follicle passage. A granu- viduals. Use of the 585-nm pulsed dye laser has led to
similar-appearing disease states. lomatous form of rosacea can be seen histologically. excellent results in treating the underlying redness from
Histology: The findings on skin biopsy in rosacea Treatment: Sun protection and sunscreen use telangiectatic blood vessels. Isotretinoin has been used
depend on the form that is biopsied. The erthema- are important for all patients with rosacea, especially in severe cases, including rosacea fulminans. Rhino-
totelangiectatic form typically shows a few dilated the erthematotelangiectatic form. The use of topical phyma is typically treated with a surgical approach to
blood vessels and dermatoheliosis. A sparse, superficial and oral antibiotics (e.g., topical metronidazole, debulk the extra tissue and reshape the nose.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 139