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Acne necrotica
introduction
Among the various scarring alopecias, further histopathologic (the
study of microscopic changes in diseased tissues) distinction is
made between neutrophilic, lymphocytic, and mixed types of alopecia,
based on the inflammatory infiltrate.
Acne necrotica is a clinically distinct necrotizing disorder of
the hair follicle that is classified as a mixed alopecia. Necrosis
is the death of cells or tissues through injury or disease, especially
in a localized area of the body. Also known as folliculitis necrotica,
acne necrotica is a chronic relapsing hair disorder commonly involving
the anterior (front) hairline in adults. Usually, 5 to 20 nectrotic
pustules in the hairline are the signs of early disease, and manifestations
of late stage disease are irregular scars that look like those of
small pox.
One school of thought is of the opinion that there are two forms
of acne necrotica: acne necrotica varioliformis and acne necrotica
miliaris. But other authors opine that acne necrotica or folliculitis
necrotica, as it is also known, should not be confused with acne
necrotica miliaris as the latter is a non scarring superficial folliculitis
that is characterized by minute, very itchy pustules within the
scalp. This article is focused on the acne necrotica varioliformis
scarring alopecia form.
As is the case with all scarring alopecias, the etiology of acne
necrotica is not clearly known. Theories purport that the condition
maybe an abnormal host response to the bacterium Staphylococcus
Aureus or Propinibacterium Acnes folliculitis. Necrotic excoriation
or erosion / destruction of the skin by mechanical insult like a
scratching, abrasion or rubbing of the skin prompted by an underlying
folliculitis could be another cause of acne necrotica. Some literature
suggests the origin to be akin to that of rosacea, a hereditary,
long term skin disorder that most often affects the nose, forehead,
cheekbones, and chin.
Acne necrotica
clinical features
Acne necrotica or folliculitis necrotica are present in adults
as pruritis or painful follicular papules (small, solid, usually
inflammatory elevations of the skin that do not contain pus) or
follicular papulopustules. These papules characteristically develop
a central mark or depression resembling a navel (umbilication) and
a round adherent crust. Men appear to be more prone to acne necrotica
than women. The frontal and parietal scalp is characteristically
involved, but it is not unusual to find the seborrheic regions of
the face, neck and chest, where there is over activity of the sebaceous
glands, are also affected.
Crops of pin-head to pea sized pustules appear in the early stages
of acne necrotica. These pustules may be itchy, reddish brown papules
or in the form of papulopustules. The pustules gradually umbilicate,
and then undergo chronic necrosis (death of cells or tissues), leaving
round hemorrhagic crusts that are shed a few weeks later.
This process results in “punched out” depressed scars,
which appear as focal areas of cicatricial alopecia when terminal
hair-bearing areas are affected. A few lesions typically appear
with each outbreak. Reportedly, summer heat can cause aggravation
of the condition. Scars that appear perforated like a sieve cause
cosmetic disfigurement when the disease reaches chronic proportions.
Acne necrotica
differential diagnosis
Most scarring alopecias exhibit overlapping features and it is
not easy for the dermopathologist to differentiate all the clinical
and morphologically distinctive variants of scarring alopecia, leading
to misdiagnoses. A clear understanding of the clinical and histological
presentation of acne necrotica is crucial to the diagnosis.
Early stages of acne necrotica may be difficult to differentiate
from conventional folliculitis due to overlapping of features. Neurotic
excoriations, acne necrotica miliaris, folliculitis decalvans, eczema
herpeticum, conventional folliculitis, and molluscum contagiosa
should be differentiated from acne necrotica varioliformis. Acne
necrotica miliaris is not associated with exclusive involvement
of the anterior portion of the scalp. Neurotic excoriations are
lesions produced by patients because of repetitive skin picking.
Eczema herpeticum patients often present with clusters of umbilicated
vesicles that evolve into classic discrete "punched-out" small
erosions within days. Molluscum contagiosa is growth on the skin
which looks like little white pearls, caused by a group of viruses.
The early pathological findings of acne necrotica are represented
by a necrotizing lymphocytic folliculitis and differ from the pattern
seen in association with nonspecific excoriations, acute bacterial
folliculitis, classic comedogenic acne or acnitis.
Acne necrotica
pathology
When diagnosing the various forms of alopecia, skin biopsies are
performed to help differentiate between skin conditions with overlapping
clinical features. Sometimes, different skin conditions can look
similar to the naked eye, and the additional information obtained
by looking at the structure of the skin under the microscope can
give valuable leads for conclusive diagnosis. The scalp biopsy is
a simple procedure in which a small area of the scalp is removed
after numbing anesthetic medication is administered. The site chosen
for scalp biopsy is crucial to the evaluation, as the information
obtained from a hair bearing site with active disease is more productive
than from bald or end-stage diseased areas of the scalp. An appropriate
histopathology report on scarring alopecia should note the follicular
architecture; the type, location, and extent of inflammatory infiltrate;
and the presence or absence of sebaceous glands.
An obliterative, suppurative (with pus), necrotic, infundibular
folliculitis is the diagnostic hallmark of acne necrotica. Folliculitis
is the name given to a group of skin conditions in which there are
inflamed hair follicles, and folliculitis is obliterative when the
natural space within the follicle is filled by fibrosis. The folliculitis
in acne necrotica is primarily lypmphocytic in nature in the early
stages of the disease but it becomes mixed later as the disease
progresses. The late pathological presentations of folliculitis
decalvans, such as sinus tracts and deep hair shaft granulomas are
not observed in acne necrotica.
Biopsies of early acne necrotica lesions show spongiosis or intracellular
edema of the epidermis. There is also the development of multiple
individual necrotic keratinocytes within the follicular sheath and
adjacent epidermis with lymphocytic exocytosis. Exocytosis is the
appearance of migrating inflammatory cells in the skin epidermis.
In later lesions a more intense necrosis and a scaly crust is observed.
These lesions are still dominated by a peripheral lymphocytic infiltrate.
As the disease advances, coalescing necrosis of the adjacent epidermis
and dermis occurs, culminating in a zone of destruction interspersed
with fragmented bits of hair.
Acne necrotica
treatment
Because only the superficial portion of the follicle is involved
in early disease, regeneration of follicles and hair re -growth
may be possible with early treatment intervention. Awareness of
the disease, detailed history, thorough physical examination and
interpretation of appropriate laboratory procedures, like a scalp
biopsy, are crucial to the correct diagnostic conclusion and commencement
of therapy. The documentation of research offers dermatologists
a practical approach to diagnosis, insight into the possible mechanisms
of various forms of alopecia, as well as a therapeutic updates.
Favorable degrees of improvement in acne necrotica have been noted
with the following methods:
- Oral tetracyclines, anti staphylococcal agents and anti
bacterial shampoos can provide relief.
- Use of isotretinoin,
a chemical compound that inhibits the secretion of sebum, in
case of propinibacterium acnes or in severe, recalcitrant cases
can lead to prolonged remission.
- Simultaneous treatment of localized areas
of the body suspected to be bacterial carriage areas with topical
antibiotics has also contributed
to positive results.
Acne necrotica, also known as folliculitis necrotica, ‘acne
varioliformis’ or ‘acne frontalis’ is a severe
form of scalp folliculitis in which larger follicular spots become
inflamed then develop blackened crusts, finally leaving permanent
pox-like scars. Acne necrotica may affect the face, scalp or other
areas.
Acne necrotica
references
- Zirn JR, Scott RA, Hambrick GW. Chronic acneiform
eruption with crateriform scars. Acne necrotica (varioliformis)
(necrotizing lymphocytic folliculitis).
Arch Dermatol. 1996 Nov;132(11):1367, 1370.
PMID: 8915319
- Milde P, Goerz G, Plewig G. [Acne necrotica (varioliformis).
Necrotizing lymphocytic folliculitis] Hautarzt. 1993 Jan;44(1):34-6.
PMID: 8436506
- Kossard S, Collins A, McCrossin I. Necrotizing
lymphocytic folliculitis: the early lesion of acne necrotica (varioliformis).
J Am Acad Dermatol. 1987 May;16(5 Pt 1):1007-14.
PMID: 2953765
- Mittal R, Chopra A, Gupta S. Acne necrotica.
Indian J Dermatol. 1985 Apr;30(2):45-8. PMID: 3843233
- Hunter GA. Acne necrotica due to phenylbutazone.
Br Med J. 1959 Jan 10;30(5114):113. PMID:
13608095
- Stritzler C, Friedman R, Loveman AB. Acne necrotica; relation
to acne necrotica miliaris and response
to penicillin and other antibiotics. AMA Arch Derm Syphilol. 1951
Oct;64(4):464-9. PMID: 14867857
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