84th Annual Meeting of Fumaric Acid Esters for Severe
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Transcript 84th Annual Meeting of Fumaric Acid Esters for Severe
M62 Course – Cedar Court Hotel, Huddersfield
7th April 2005
The Dermatologist and
Pruritus Ani
MJ Harries and CEM Griffiths
Dermatology Centre, Hope Hospital,
Manchester, UK
“An unpleasant cutaneous
sensation that induces the desire
to scratch the skin”
Itch-Scratch Cycle
DAMAGED
PERIANAL SKIN
PRURITUS
SCRATCHING
Classification of Itch
Pruritoceptive itch
Originates in the skin
Neurogenic itch
Originates in the
nervous system
Itch specific neuronal
pathway (C-fibres and
spinothalamic tracts)
Yosipovitch et al. Lancet 2003; 361:690-694
Causes of Pruritus Ani
Anal pathology
Infections
Skin disease
Contact allergy
Underlying medical conditions
Idiopathic
Causes of Pruritus Ani
Anal pathology
Infections
Skin disease
Contact allergy
Underlying medical conditions
Idiopathic
Skin Disease
85% consecutive patients referred to a
combined colorectal and dermatological clinic
had an underlying dermatosis
Over half had a positive patch test
“Patients with long-standing pruritus ani with no
other symptoms to suggest colorectal pathology
should be referred to a dermatologist for
assessment and patch testing.”
Dasan et al. Br J Surg 1999; 86: 1337-40
Psoriasis
2% population
Approx. 1.2 million
sufferers in the UK
Immune-mediated
disease
Positive family history
common
Psoriasis
Symmetrical
Extensor aspects
Elbows / knees
Scalp
Umbilicus
Natal cleft
44% perianal
involvement
Farber et al. Dermatologica 1974;148:1-18
Psoriasis - Perianal
Psoriasis - Perianal
Where else to look?
Where else to look?
Lichen Planus
Idiopathic
inflammatory disease
of the skin and
mucous membranes
Common sites
Flexor wrist
Anterior lower leg
Neck
Presacral area
75% oral involvement
Lichen Planus
Polygonal,
violaceous, flattopped papules
Wickham’s striae
Pruritus +++
Lichen Planus - Perianal
Lichen Planus - Perianal
Where else to look?
Where else to look?
Lichen Sclerosis
Idiopathic
inflammatory disease
that preferentially
affects the anogenital
region
Hypopigmented and
atrophic skin
Figure-of-eight
distribution (women)
5% risk of SCC
Lichen Sclerosis - Perianal
Seborrheic Eczema
Link with sebum
overproduction and
the commensal yeast
Malassezia furfur
Red-brown patches
with “greasy” scale
Common sites
Scalp
Nasolabial folds
Central chest / back
Flexures
Where else to look?
Lichen Simplex – The Itch that
rashes
Itching often localised
to one site resulting in
lichenification
Itch / scratch cycle
develops
Common sites
Perineum
Scrotum / vulva
Posterior neck
Lateral lower legs
Lichen Simplex - Perianal
Allergic Contact Dermatitis
55 / 80 (69%) clinically relevant allergic
reactions
38 of these reactions to medicaments or
their constituents
Improvement or resolution of symptoms in
¾ patients with avoidance advice
Advise patch testing at an early stage
Harrington et al. BMJ 1992; 305: 955
Eczema - Perianal
Patch Test
Common allergens
placed into Finn
chambers
35 common allergens
tested in the BCDS
standard series
Extra allergens tested in
the perineal series
Type IV delayed
hypersensitivity response
Patch Test – 0h
Patch Test – 48h
Patch Test – 96h
Grading system for
reactions
Negative
+/- Doubtful
+ Weak
++ Strong
+++ Very strong
Common Perianal Allergens
Local anaesthetics
Corticosteroids
Neomycin
Perfume
Preservatives
Antiseptics
Goldsmith et al. Contact Dermatitis 1997;
36: 174-5
Pruritus Ani and Underlying
Medical Conditions
Consider a “pruritus
screen” if generalised itch
is also present
Common causes include
Iron deficiency
Renal failure
Hepatic/ biliary disease
Malignancy
FBC
Ferritin / serum Fe / % sat /
TIBC
ESR
U&E
LFT
TFT
Glucose
Calcium
Serum electrophoresis
CXR
Idiopathic Pruritus Ani
Faecal contamination
Difficulty in cleaning the area
Anal sphincter dysfunction
Farouk et al. Br J Surg 1994; 81: 603-606
Dietary causes
Lumbosacral radiculopathy
16 / 18 (80%) lubosacral radiculopathy confirmed by N.C.S
Paravertebral injections of steroid / lignocaine resulted in
reduced pruritus
Cohen et al. J Am Acad Dermatol 2005; 52 :61-6
Treatment - General Advice
Wash after every B.O
and twice a day
Avoid irritants
Keep the area dry
Wear cotton
underwear
Keep bowels regular
Alexander-Williams J. BMJ 1983;287:1528
Topical Steroids
Mild, moderate, potent and very potent
Treats inflammation
Break the itch-scratch cycle
As control is achieved the potency should be
reduced
If not improving consider
?Appropriate potency for condition
?steroid allergy – Patch test
?correct diagnosis - Biopsy
Other Treatments
Topical Capsaicin
Placebo controlled trial
0.006% capsaicin cream t.d.s for 4 weeks
31 / 44 (70%) responded
Lysy et al. Gut 2003; 52: 1323 – 1326
Intradermal methylene blue injections
1% methylene blue / hydrocortisone / lignocaine
88% patients responded
Botterill et al. Colorectal Dis 2002;4:144-6
Summary
Examine the entire skin surface including
nails and mucous membranes
Consider patch testing early in
management
Consider skin biopsy if any diagnostic
doubt or if the condition is not responding
to appropriate treatment