Lecture Notes Dermatology - Graham-Brown, Robin, Burns, Tony

58 Acne, acneiform eruptions and rosacea
notably systemic steroids, phenytoin, isoniazid
and lithium.
Oil - induced acne occurs when mineral oils
come into close contact with the skin. This is often
at unusual sites, such as the lower abdomen and
thighs.
Chloracne is a specific change in which comedones
appear after exposure to chlorinated chemical
compounds. Famous examples are the release
of dioxin from an explosion at Seveso in Italy and
the poisoning of a prominent Ukrainian politician.
Systemic upsets also occur.
(a)
Hidradenitis s uppurativa
Although uncommon, this distinctive disorder
results in very unpleasant, chronic, relapsing
sepsis in the apocrine areas of the axillae and
groins (Figure 6.7 ). Many apocrine glands open
into the upper part of pilosebaceous follicles and
comedonal occlusion of the ducts may be the
initial event in hidradenitis.
Recurrent painful abscesses and sinus tracks
develop. Many patients with hidradenitis have
concurrent severe acne, or have had acne in the
past.
Some patients improve on long - term antibiotics
(including agents with activity against anaerobic
bacteria), antiandrogens and/or isotretinoin, but
many require plastic surgery.
Acneiform d isorders
Several conditions mimic acne, but close examination
will reveal important differences.
Pseudofolliculitis barbae (shaving rash): produces
small papules in the beard area and is more
common in those with naturally curly hair, especially
African – Caribbean individuals. Occasionally
small keloids develop. The process may involve
the nape of the neck, when it is usually termed
‘ acne keloidalis ’ . Treatment is unsatisfactory.
Acne excori é e ( des jeunes filles ) is typically seen
in teenage girls who present with facial excoriations
but very few primary lesions. There are no
comedones. This is a form of neurotic excoriation
(see Chapter 20 ), and patients need to be given a
clear explanation and helped to try and reduce the
self - inflicted damage.
(b)
Figure 6.7 Hidradenitis suppurativa of (a) axilla and
(b) groin.
Pityrosporum folliculitis, caused by Malassezia
sp., features follicular papules and pustules on
the trunk, without other features of acne. The condition
responds to antifungal agents such as
miconazole.
In keratosis pilaris, small spiky projections
develop at the mouth of hair follicles, especially on
the upper, outer arms and shoulders. Lesions may
appear on the face, especially in children, and are
occasionally pustular. A family history is common.
Topical retinoic acid may be helpful.
Rosacea is an important differential diagnosis of
acne, and is sometimes erroneously called ‘ acne
rosacea ’ . It occurs in both sexes, but most frequently
affects middle - aged women. The sites of
predilection are the central cheeks, forehead and
glabellar region, end of the nose and chin (Figure