M62 Course – Cedar Court Hotel, Huddersfield 7 th April 2005 The Dermatologist and Pruritus Ani MJ...
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Transcript of M62 Course – Cedar Court Hotel, Huddersfield 7 th April 2005 The Dermatologist and Pruritus Ani MJ...
M62 Course – Cedar Court Hotel, Huddersfield 7th April 2005
The Dermatologist and Pruritus Ani
MJ Harries and CEM GriffithsDermatology Centre, Hope Hospital,
Manchester, UK
“An unpleasant cutaneous sensation that induces the desire
to scratch the skin”
Itch-Scratch Cycle
PRURITUS
SCRATCHING
DAMAGED PERIANAL SKIN
Yosipovitch et al. Lancet 2003; 361:690-694
Classification of Itch
Pruritoceptive itchOriginates in the skin
Neurogenic itchOriginates in the
nervous system
Itch specific neuronal pathway (C-fibres and spinothalamic tracts)
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 aspectsElbows / kneesScalpUmbilicusNatal 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 sitesFlexor wristAnterior lower legNeckPresacral area
75% oral involvement
Lichen Planus
Polygonal, violaceous, flat-topped 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 sitesScalpNasolabial foldsCentral chest / backFlexures
Where else to look?
Lichen Simplex – The Itch that rashes
Itching often localised to one site resulting in lichenification
Itch / scratch cycle develops
Common sitesPerineum Scrotum / vulvaPosterior neckLateral 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 regularAlexander-Williams J. BMJ 1983;287:1528
Topical Steroids
Mild, moderate, potent and very potentTreats 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 CapsaicinPlacebo controlled trial0.006% capsaicin cream t.d.s for 4 weeks 31 / 44 (70%) responded
Lysy et al. Gut 2003; 52: 1323 – 1326
Intradermal methylene blue injections1% methylene blue / hydrocortisone / lignocaine88% 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