Page 159 - The Netter Collection of Medical Illustrations - Integumentary System_ Volume 4 ( PDFDrive )

Plate 4-74 Rashes
SKIN MANIFESTATIONS OF CUTANEOUS MANIFESTATIONS OF INFLAMMATORY BOWEL DISEASE
INFLAMMATORY BOWEL DISEASE
(Continued)

when the inflammatory bowel disease re cognizes the
skin as gut tissue and develops the same granulomatous
process within the cutaneous structures.
Histology: Pyoderma gangrenosum shows non-
specific ulceration when biopsied. The findings are
nondiagnostic, and the diagnosis is one of exclusion. Cribiform ulceration with a purple
The presence of multiple neutrophils leads one to look surrounding border is characteristic
for cutaneous infection, and appropriate tissue cultures of pyoderma grangrenosum.
should be performed and found negative before a diag-
nosis of pyoderma gangrenosum is made. The appear-
ance of pyoderma gangrenosum histologically is highly
dependent on the time and type of lesion biopsied.
Early lesions show a follicle-centered neutrophilic
infiltrate with a dermal abscess. As the lesions prog-
ress, ulceration is seen with a predominant neutro-
philic infiltrate. The ulcers are often very deep and
enter the subcutaneous tissue. Changes of vasculitis
can often be seen, but they are believed to be caused
by the overlying ulceration; the vasculitis is not
thought to be the predominant pathological process.
Biopsy specimens of erythema nodosum shows a
septal panniculitis. The fibrous septa are inflamed with
a mixed inflammatory infiltrate with heavy lymphocyte
predominance. Giant cells are frequently seen within
the widened septal tissue. A unique finding is that of Older lesion of pyoderma gangrenosum
Miescher’s radial granuloma formation, in which mul- with granulation tissue present. The
tiple histiocytes are arranged flanking a small area. rolled borders are not as prominent as
They are organized circumferentially around a central in acute lesions. Erythema nodosum manifesting
slit-like space. The reason for this finding is unknown. as tender dermal nodules
Erythema nodosum is the most common form of septal
panniculitis.
Aphthous ulcerations, if biopsied, show small ulcer-
ations or erosions of the mucosa. The predominant cell
type found within the infiltrate is the neutrophil. These
findings are nonspecific.
Oral candidiasis should be diagnosed without a skin
biopsy. A scraping of the white oral plaques shows an Crohn’s disease
easily removed, whitish, sticky tissue. A microscopic
examination shows candidal elements. Examination of
the biopsy specimen shows the candidal organisms on
the surface of the mucosa, with an underlying mixed
inflammatory infiltrate.
Metastatic Crohn’s disease is a unique phenomenon.
It is histologically described as noncaseating granulo-
mas. These granulomas are identical to the bowel
granulomas. The skin granulomas are centered in the
dermis but can be seen around blood vessels and into
the adipose tissue. External fistula (via appendectomy incision)
Treatment: Therapy is aimed at controlling the
underlying bowel disease. If it is well controlled, the
skin manifestations typically follow in line. Conversely,
if the bowel disease is poorly controlled, one can expect
the skin disease to be poorly controlled as well. It is
useful to use the skin manifestations as a sign of active Perianal fistulae and/or abscesses
bowel disease. If a patient who has been in a long remis-
sion suddenly develops pyoderma gangrenosum, it is
highly plausible that the bowel disease has become
active once more. Ulcerative colitis can be cured by
colectomy. Crohn’s disease cannot be cured by colec- the skin disease. Cyclosporine and prednisone have Erythema nodosum can be treated with compres-
tomy because it affects the entire gastrointestinal tract. shown excellent results in treating pyoderma gangreno- sion stockings, topical potent steroids, and oral ste-
Oral or intravenous immunosuppressive medications sum. Intralesional triamcinolone can be attempted on roids in severe cases. Intralesional injection of
are used to treat both these conditions. Oral predni- small, early lesions of pyoderma gangrenosum. triamcinolone is also effective. Metastatic Crohn’s
sone, sulfasalazine, azathioprine, methotrexate, myco- Oral aphthous ulcers can be treated with topically disease is difficult to treat and requires systemic
phenolate mofetil, and intravenous infliximab have applied steroid gels or ointments compounded in dental immunosuppressive agents such as azathioprine, pred-
shown excellent results in patients with these chronic paste formula to increase adherence to the mucosa. nisone, or infliximab. It is best treated by a multi-
diseases. They also have the added benefit of helping Topical anesthetics are commonly used. disciplinary approach.

THE NETTER COLLECTION OF MEDICAL ILLUSTRATIONS 145