Perineal/perianal Skin Flashcards
History
History of topical treatments including OTC remedies
Wet wipes
Toiletries
Examination
Local exam
Woods lamp helpful for erythrasma, vitiligo
Extragenital skin
Investigations
Bacterial swab Viral swab Fungal scrapings Urine for glucose Pelvic MRI, endoanal USS useful in anal fistula, anal malignancy Allergy patch testing if suspect ACD Sellotape test if suspect threadworms Stool exam
Signs of spinal dysgraphism I.e. Spina bifida
Congenital hypertrichosis over the midline in lumbosacral area (faun tail)
Congenital naevi
Hamartomas
Idiopathic (primary) pruritus ani predisposing factors
Faecal contamination and it’s causes -
Difficulty cleaning - obesity, anatomical factors (deep funnel anus, hirsutism)
Anal leakage - haemorrhoids, perianal tags, fissures, primary anal sphincter dysfunction, caffeine lowers anal resting pressure
Loose frequent stools I.e. IBS
Food and drink (role uncertain) - coffee, tea, cola, beer, chocolate, tomatoes, spices, citrus
Psychological - stress, anxiety
Secondary pruritus ani causes
Inflammatory - Endogenous eczema I.e. seb derm, atopic eczema ICD ACD Psoriasis Lichen planus Urticaria Lichen sclerosis (females only) HS
Infectious - Candida (exclude diabetes in severe and persistent infection) Dermatophyte Erythrasma (corynebacterium) Staph aureus Beta-haemolytic strep Gonorrhoea Syphilis HPV HSV HIV
Infestations -
Threadworms (enterobius vermicularis)
Pubic lice (phthiriasis pubis)
Premalignant/malignant -
EMPD
Anal intraepithelial neoplasia
Anal carcinoma
Ano-rectal disease - Haemorrhoids Anal fissure Perianal fistula Perianal abscess IBD
Systemic disease - Iron deficiency anaemia Diabetes Renal, thyroid, liver disease Leukaemia, lymphoma
Common allergens in perineal/perianal ACD
Neomycin Fragrance mix Balsam of Peru Methylisothiazolinone Condom allergy Spermicide allergy
Management of pruritus ani
General measures -
Address secondary causes
Attention to washing habits
Maintain cleanliness
Ensure area dried after washing
Soap substitutes
Wash off shampoo residue
Apply emollient after each wash
Pre-apply barrier cream before bowels open
Washing in a bidet preferable to wiping with toilet paper
If using toilet paper, dab and not rub
Avoid wet wipes/pre-moistened toilet paper
Loose cotton underwear
Avoid topical anaesthetic preparations (causes sensitisation)
Keep fingernails short
Reduce coffee consumption
Eliminate implicated food and drinks
If history of haemorrhoids, encourage high fibre diet
Referral - colorectal if suspect ano-rectal disease
First line -
BD liquid cleanser
BD 1% hydrocortisone ointment (caution with TCS due to risk of atrophy infection in occluded skin) +/- antibacterial/anti fungal
Second line - Zinc paste + 1-2% phenol 0.006% capsaicin ointment 0.1% tacrolimus ointment Oral antihistamines ILCS Corticosteroid suppositories
Third line -
Intradermal 1-2% methylene blue +/- 0.5% lignocaine
Cryotherapy
Inflammatory Dermatoses in the perineal/perianal skin
Seb derm - brownish red with large greasy scales towards the edge extending beyond natal cleft
Psoriasis - dull red hue, smooth glazed surface, fissured
Lichen simplex - unilateral
Fungal infection - suspect if prior TCS use
ACD - ill-defined spreading border, very inflamed, blisters
ICD - urine, faeces, laxatives containing danthon
Lichen sclerosus - figure of 8 distribution (Vulval to perianal skin), perianal only in women (assoc with urinary incontinence and contact of perianal skin with urine),
Lichen planus - very itchy (excoriated, hypertrophic), may be solitary involvement, Wickham’s striae
Harley-Hailey disease (biopsy helpful to confirm) - exacerbated by heat, friction, infection, contact dermatitis
Acrodermatitis enteropathica - malnutrition, malabsorption
Cicatricial pemphigoid - inflammation, ulceration, scarring leading to anal stenosis
SJS - inflammation, ulceration, scarring leading to anal stenosis
Behcet disease - shallow ulcers/fissures of the anal margin
Radiodermatitis - following treatment for anal CA
Drug reactions in perineal/perianal skin
Fixed drug eruption - pigmentation
Atrophy - from prolonged TCS - dusky erythema, telengiectasia, atrophy, induration, acneform lesions/comedones
Contact dermatitis - topical imiquimod (ICD or ACD)
Perianal ulceration - from Nicorandil
Bacterial folliculitis/furunculosis in perineal/perianal skin predisposing factors
High temperature, Humidity, Pressure, Friction encourage colonisation with staph aureus
Poor personal hygiene
Hyperhidrosis
Obesity
Anaemia
Personal/family Hx atopic eczema
Nasal carriage of staph aureus
Immunodeficiency I.e. HIV, diabetes, malnutrition (recurrent furunculosis)
EGFR inhibitors I.e. cetuximab (folliculitis)
Bacterial folliculitis/furunculosis in perineal/perianal skin causative organisms
Staph aureus (commonest)
MRSA
Pseudomonas (hot tub/wet suit folliculitis)
Malassezia furfur (pityrosporum folliculitis)
Klebsiella (gram neg folliculitis)
HSV
DDx of folliculitis/furunculosis in perineal/perianal skin
HS
Pilonidal sinus
Crohn disease
Investigations for folliculitis/furunculosis in perineal/perianal skin
Bacterial swab
Viral swab
Fungal scrapings
Nasal swab +/- other carrier sites (patient, consider for close contacts)
Treatment ladder folliculitis/furunculosis in perineal/perianal skin
General measures -
Antibacterial soap
Good personal, interpersonal, environmental hygiene
First line -
Topical antibiotics (superficial folliculitis)
Systemic antibiotics as guided by MCS (furunculosis)
Other -
I&D
Topical decolonisation regimen in recurrent furunculosis, MRSA
Streptococcal dermatitis (perianal cellulitis) features
Group A beta-haemolytic strep Boys 6 -10 months, sometimes adults Itch, perianal pain, painful,defaecation Sharply demarcated boggy erythema Satellite pustulosis on buttocks May trigger guttate psoriasis Treat with systemic antibiotics
Ano-genital cellulitis features
Cysts, sinuses, fistulae
Abscess
DDx - Staph cellulitis Strep cellulitis Gonococcal cellulitis Necrotising soft tissue infections i.e. necrotising fascitis (strep, clostridium) HS Crohn disease EMPD Carcinoma erysipeloides
Necrotising fasciitis features
Often middle aged/elderly
Risk factors - diabetes, IVDU, trauma, haem malignancy
Extreme pain, out of proportion to physical signs
Fever, cellulitis, then distinct dusky red to black spot with extreme rapidity
Crepitus
Dark brown turbid fluid without pus
Rapid deterioration and septicaemia
Surgical debridement
