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
Ecthyma gangrenosum features
Pseudomonas aeruginosa septicaemia Immunosuppressive/critically ill Predilection for ano-genital region Severe, painful, necrotising ulcers High mortality
Perianal TB features
Indolent irregular ulcers, fistulae, abscesses
Fumigating, vegetative appearance (lupus vulgaris)
painful
Fungal infections in perineal/perianal skin
Consider this for unusual perianal dermatitis and perform MCS
Candidiasis (bright red glazed with outlying small pustules)
Dermatophyte I.e. T rubrum (well defined scaly patch with circinate edge)
Histoplasmosis
Blastomycosis
Viral infections in perineal/perianal skin
HSV (ulcerated inflamed skin on buttocks, perianal skin)
HPV
CMV (perianal ulcers) - setting of HIV
Kawasaki disease (red desquamating perineal eruption in 1st week of disease)
Helminth infections in perineal/perianal skin
Strongyloides stercoralis chronic infection (filariform larvae passed in the stool attach to perianal skin and lead to autoinfection by migrating through skin) - larva currens (very itchy red papules and serpiginous tracts on perianal, buttock, upper thigh)
Cutaneous larva migrans (infective larvae from dog/cat hookworms)
Schistosomiasis (perineal itchy granulomatous papules in endemic countries)
Other parasitic infections in perineal/perianal skin
Scabies (sarcoptes scabiei var hominis) - nodules buttock, perineum
Amoebiasis (antamoeba histolytica) - perianal abscess, ulcer
STDs in the perineal/perianal skin
Particularly MSM, HIV positive men
Ulcers
Syphilis (treponema pallidum) - primary chancre (primary syphilis), condylomata lata (secondary syphilis), granulomatous gumma (tertiary syphilis)
Gonorrhoea (neisseria gonorrhoea) - oedema, discharge, fissures, erosions
Lymphogranuloma venereum (chlamydia trachomatis) - ulcerative haemorrhagic proctitis mimicking Crohn’s colitis
Granuloma inguinale, Donovanosis (klebsiella granulomatis) - PAINLESS papules/nodules that ulcerate, risk SCC
Chancroid (haemophilus ducreyi) - PAINFUL ulcers, inguinal lymphadenopathy
HPV - anal warts (not always STD)
HSV 2 - ACUTE PAINFUL ulcers, proctitis without perianal ulcers
Pubic lice (phthiriasis pubis)
Causes of anal/perianal ulcers in setting of HIV positive men/women
Infective -
HSV
CMV
Syphilis I.e. primary chancre (treponema pallidum)
Lymphogranuloma venereum (chlamydia trachomatis)
Amoebiasis
Anal sepsis (perianal abscess, fistula)
Malignancy -
Kaposi sarcoma
Non-Hodgkin lymphoma
SCC
Idiopathic I.e. aphthous ulcer
Structural -
Anal fissure
Haemorrhoids
Other -
Trauma
Pruritus ani
HPV infection in the ano-genital region (ano-genital warts/condyloma acuminata)
Commonest viral STD in this region
HPV types 6, 11 - benign warts
HPV types 16, 18 - anal intraepithelial neoplasia, anal CA
Higher in men, especially MSM
HPV infection predisposing factors
Ano-receptive sex
Increase lifetime sexual partners
Immunosuppression
Ano-genital wart pathology
Hyperkeratosis Parakeratosis Papillomatosis Acanthosis Coarse keratohyaline granules in the granular layer Koi located in the granular layer
DDx of ano-genital warts
Molluscum contagiosum Condyloma lata (secondary syphilis) Lichen planus Anal intraepithelial neoplasia Anal CA
Complications of ano-genital warts
Risk of ano-genital neoplasia, oropharyngeal CA
If immunosuppressed, higher risk of progression to anal intraepithelial neoplasia and anal CA
If MSM, higher risk of HIV
Management of ano-genital warts
REFERRALS -
Genito-urinary medicine specialist needs full sexual health screen
Colorectal if intra-anal disease suspected
INVESTIGATIONS -
Biopsy of diagnosis in doubt or dysplasia suspected
TREATMENT - First line - 5% imiquimod cream - Podophylin - Podophylotoxin - TCA
Second line
- cryotherapy
- electrocautery
- excision
- ablative laser
Third line -
- topical, intralesional, systemic interferon (not recommended as routine)
Anal intraepithelial neoplasia (carcinoma in situ, Bowen disease, Bowenoid papulosis)
HPV 16, 18
Older women
MSM
Can affect anal, perianal, vulva, cervix, penis
Anal intraepithelial neoplasia risk factors
MSM (esp with HIV) Receptive anal sex Hx ano-genital warts Lifetime number of sexual partners Smoking Immunosuppression I.e. renal transplant
Anal intraepithelial neoplasia path
Epidermal Cytological atypia Dyskeratosis Nuclear pleomorphism Nuclear hyperchromatism Mitoses Koilocytes may be present p16 (proliferative biomarker) can be useful for grading of severity
Anal intraepithelial neoplasia clinical features
Often asymptomatic Can be itchy, bleeding Solitary vs multifocal Intra-anal lesions may be papillomatous, red, white, pigmented, fissured Induration/ulceration (sign of invasion)
Variants -
- Perianal Bowen disease - asymptomatic red shiny scaly plaque, may be continuous with dysplastic lesions in anal canal, Risk of progression to invasive SCC
- Bowenoid papulosis - solitary/multiple reddish brown/pigmented/flesh-coloured flat/verrucous papules, unknown risk of progression to invasive CA
Anal intraepithelial neoplasia DDx
Anal CA
HPV infection
Psoriasis
Lichen planus
Anal intraepithelial neoplasia course/prognosis
Risk of progression to anal/perianal SCC poorly understood
Anal epithelial neoplasia investigations
Biopsy - confirm Dx, evidence of invasive disease
High resolution anoscopy with mapping biopsies of suspicious areas
Anal intraepithelial neoplasia management
Aims -
Alleviate symptoms
Prevent progression to anal CA
Close follow up
General measures -
MDT approach
Examine genital skin for associated diseases I.e. warts
Colorectal - Digital rectal exam, anoscopy (determine if any intra-anal disease)
Gynae for females - exclude concomitant CIN
First line - Top 5% imiquimod Top 5-FU Electrocautery CO2 Laser ablation Excision (small solitary perianal lesions) —> risk of anal stenosis, faecal incontinence
Second line -
PDT
Screening/prevention -
HPV vaccine in MSM
No national screening program
Controversial use of anal cytology, high resolution anoscopy due to cost-effectiveness
Recommended in high risk population I.e. MSM, HIV
Extramammary Paget disease (EMPD)
Primary - intraepithelial adenoCA from apocrine gland ducts intraepidermal cells/pluripotent keratinocyte stem cells (neoplastic cells showing glandular differentiation), CA in situ but can become invasive, metastatic
Secondary - epidermal involvement from an internal neoplasm, either by direct extension or metastasis
Secondary EMPD Associations -
Ano-rectal adenoCA (especially with perianal EMPD)
Bladder/urethra adenoCA
Other adenoCA
Pruritus
Burning
Perianal bleeding
Red plaques/erosions, moist, hyperkeratotic “strawberries and cream”
Sharp border
Solitary vs multifocal
Variable hyperpigmentation
Thickened/ulcerate (sign of invasion)
Sites rich in apocrine glands I.e. vulva, Anogenital skin, scrotum, penis, axilla
Perianal lesions can extend into anal canal
Vulval lesions can extend to introitus
DDx - Psoriasis Eczema Vulval/anal intraepithelial neoplasia Bowen disease
Histo -
Epidermal hyperplasia
Paget cells (large vacuolated cells with circular nuclei, foamy pale cytoplasm) infiltrate epidermis
IHC primary + secondary EMPD - PAS + CAM5.2 + (LMW keratin) CK7 + (LMW keratin) CEA + Pankeratin - (excludes carcinoma) CK5/6 - (excludes carcinoma) S100 - (exclude melanoma) Melan A - (exclude melanoma)
Differentiating IHC for primary vs secondary EMPD = CK20, GCDFP-15
Primary EMPD CK20 - GCDFP-15 + (marker of apocrine epithelium)
Secondary EMPD CK20 + GCDFP-15 -
Investigations -
Full exam for extent and an underlying adenoCA esp cervix, rectum
Skin Biopsy
Ensure cervical cytology/mammogram UTD (female)
Consider bowel/urological investigation
Primary EMPD Treatment (combo often needed) - Excision with large margins (first line) MOHS Top 5-FU Top 5% imiquimod (widespread disease, for post-surgery recurrence) Top bleomycin Oral retinoids Cryotherapy PDT CO2 ablative laser RTX (adjunct to surgery or if surgery not possible) TCS if itchy Regular monitoring
Secondary EMPD Treatment -
Treat underlying CA
Course/prognosis -
Indolent, but spreads by local extension and mets
Recurrence common
Excellent prognosis for primary intraepithelial disease, less so for invasive disease
Other malignancies
EMPD
BCC - predisposed from radiation, trauma, burns
Melanoma
LCH
Carcinoma erysipeloides
Carcinoma erysipeloides
Infiltration of the skin with neoplastic cells
Infiltrated papules
Associated malignancies -
Bladder, prostate CA (perineum, thigh)
Colon adenoCA (genito-crural region)
Anal/perianal cancer
Anal canal or anal margin or both
Subtypes of anal cancer - SCC (usually preceded by anal intraepithelial neoplasia) AdenoCA Melanoma Lymphoma Kaposi sarcoma (HIV related)
Anal SCC (a subtype of anal cancer)
HPV-16, 18
Ano-receptive sex
