Dermatology Flashcards
What are the benefits of sun exposure?
What are the risks of sun exposure?
Emotional/psychological health
Vitamin D production- bone health and cancer protection
Cardiac health- treat HTN
UV-B- sunburn, direct DNA damage and carcinogenesis.
UV-A- photoaging (wrinkles), potentiates UV-B carcinogenesis, immunological effects
How is a diagnosis of skin cancer achieved?
Awareness of GP/well trained (dermatoscope) 2ww referral Dermatoscope AI technology Surgical biopsy
What is an acquired naevus?
Nevi refer to moles/birthmarks.
Moles
Flat- junctional naevus (above epidermis)
Raised- Compound naevus (@ epidermis)
Large crusty- Intradermal naevus (@dermis)
Halo naevus- nevi with ring of lightened skin surrounding it.
Premalignant- dysplastic naevus
Growing naevus in pregnancy- normal
Benign acral naevus- on hands and feet
Congenital naevus birthmark- large have a higher risk of melanoma
What is superficial spreading malignant melanoma?
Most common subtype.
Black-brown-grey-blue.
Superficial to deep invasion.
Stratify with Breslow thickness.
What is lentigo melanoma
More in head and neck
Premalignant
Invasion of sebaceuous glands with melanocytes
can progress to lentigo maligna melanoma
Malignant Melanoma mimics
Multi component hemangioma- collection of BV.
Intracorneal haemorrhage- blood under stratum corenum- turns brown in colour- scrape off wiht blade reomval.
Subungual haematoma- bleeding udner the nail plate- take serial images if unsure of diagnsis.
benign longitudianl melanonychia.
sebhoerric keratosis.
What are some differentials of BCC?
Xanthelsma
Pickers nodule- psychiatry, around the body may have other picked areas.
Benign fibrous papules- on nose usually- young women
Spitz naeuvus
Sebaceous hyperplasia- multiple, yellow
Dermatofibroma- young females, secondary to shaving or insect bites.
intradermal nevus
What are some differentials of SCC?
Inflamed squamous papilloma/viral wart
Regressing keratoacanthoma- painless, ulcerated, crater form; arising from hair follicles, may heal on its own.
Traumatised/rapid growing/inflamed SK
SK
Lymphedema nodules
Giant comedones; in acne, elderly, large keratin plugs in the middle.
Viral warts; nodular, looped vessels, keratin.
What is the importance of sunscreen?
Protection against sun harmful UV
Apply 15-30 mins before
Reapply every 2hrs
Apply in large amounts
What are the surgical excision margins for the different skin cancers?
Pigmented- 2mm
Melanoma- WLE- In siut-5mm, <2mm deopth 1cm, >2mm depth then 2cm
SCC 4+mm excision
BCC 4mm excision
What is impetigo?
Superficial bacterial infection which can be either non bullous (common) or bullous.
Non bullous- Mainly Staph aureus, but can also be Strep pneumonia or a mix of both.
Bullous- Staph aureus.
Common in younger children but can still occur in adults.
What are the signs and symptoms of impetigo?
Non bullous- small vesicles/pustules, usually around the mouth/nose area. Usually asymptomatic but may be itchy.
Bullous- Larger flaccid fluid filled vesicles/blisters for 2-3 days, appearing on flexures, face, trunk and limbs. May also have systemic features if large area involved, i.e. fever/lymphadenopathy.
How is impetigo investigated/diagnosed?
Usually a clinical diagnosis.
Take swab for MCS from a moist lesion or deroofed blister, in the case of recurrence, resistance or widespread disease.
How is impetigo managed?
Encourage hygiene to stop spread of infection.
Stay at home until lesions are dry/crusted over. If still crusted or weeping then stay at home until 48hrs after Abx treatment.
Ensuring pre-existing skin conditions (such as eczema) are optimally treated.
Non-bullous- Hydrogen peroxidase for 5 days; alternative topical Abx.
More extensive, severe or bullous infection may require oral antibiotics (flucloxacillin or clarithromycin if allergic to penicillin) for five days (or seven days depending on clinical judgment).
What is folliculitis?
Refers to inflammation of the hair follicle, commonly due to staph aureus.
Can be either superficial or deep- where deep leaves scars.
This is due to obstruction of the pilosebaceous glands +/- inefction.
What are the RF associated with folliculitis?
Uncut beard. Shaving 'against the grain'. Particularly thick hair. Excessive friction from clothing. Overly tight-fitting clothing. Excessive sweating and hyperhidrosis. High external humidity. Pre-existing dermatitis. Reduced host immunity - eg, poorly controlled diabetes, immunosuppression. Nasal carriage of infecting strains of S. aureus. Skin abrasion/wound/abscess. Occluded skin - particularly for dermatological treatment with topical corticosteroids.
What are the signs and symptoms of folliculitis?
Often appears as a small rash or area of red bumps over hairy area (painful/painless).
Pruritic
If mild and left alone, the rash usually resolves without scarring.
Pustules at the centre of lesion
Affects axilla, beard, face, scalp, thighs and inguinal regions.
Erythematous papules form in a relatively regular, sometimes ‘grid-like’, pattern.
Deep folliculitis tends to cause more erythema, becoming more confluent between the lesions, with no noticeable surface pustules and intense irritation of the skin. It can cause scarring, keloid formation and hair loss.
Regional draining lymph nodes should be checked for adenitis, which is rare in simple or mild folliculitis. Folliculitis of the eyelash is known as a stye.
How is folliculitis investigated?
Clinical diagnosis.
Swab required if recurrent or treatment resistant.
Also consider punch biopsy if atypical response to treatment.
How is folliculitis managed?
Conservatively; Reduce shaving, use clean shaving equipment, shave within the grain of the hair, use moisturiser after shaving, don’t share shaving towel/equipment with anyone in the house. Maintain good skin hygiene.
Doesn’t usually require pharmacological treatment.
Superficial; use antiseptics i.e. triclosan.
Deep; topical/oral Abx, preferred are flucloxacillin or erythromycin.
If recurrent use Abx for 4-6 weeks.
What is cellulitis?
What are the RF?
What are the complications?
- Acute bacterial infection of dermis and subcut tissues
- Typically due to strep pyogenes or staph aureus
- Risk factors- skin trauma, ulceration, obesity
- Complications- necrotising fasciitis, sepsis, persistent leg ulceration, recurrent cellulitis
What are the signs and symptoms of cellulitis?
- Commonly occurs on shins- lower limb
- Erythema, pain, swelling, warm to touch
- Blisters and bullae may form
- Systemic upsets eg fever
How is cellulitis investigated?
- Clinical- no further investigations in primary care
- In secondary care- swab for culture, ultrasonography, skin biopsy
- Bloods, BP - septicaemia
How is cellulitis classified?
Eron Classification:
Class I- No signs of systemic toxicity and Px has no other comorbidities.
Class II- Px has comorbidity which may delay recovery +/- systemic infection.
Class III- Px has significant systemic upset i.e. acute confusion, tachycardia, hypotension or unstable comorbidities.
Class IV- Px has sepsis or necrotizing fasciitis.
How is cellulitis managed?
Needs hospital admission if; Eron 3/4, rapidly deteriorating, lymphoedema, facial/peri-orbital cellulitis, child <1yrs or immunocompromised.
Other Px give:
- First-line mild-moderate cellulitis: flucloxacillin
- Penicillin allergy: clarithromycin, erythromycin (in pregnancy), or doxycycline
- Severe cellulitis: co-amoxiclav, cefuroxime, clindamycin, ceftriaxone
What is chicken pox?
Caused by varicella-zoster virus
Transmission: personal contact or droplets
- Incubation period 1-3 weeks
- Infectious from 1-2 days before the rash appears until the vesicles are dry or have crusted over, usually 5 days after rash onset
Avoid school during the highly infectious period
- The virus persists in sensory nerve ganglia of the dorsal root. Years later, it can reactivate and cause herpes zoster (shingles)
What are the signs and symptoms of chicken pox?
- Prodromal symptoms such as nausea, myalgia, anorexia, headache, general malaise, and loss of appetite.
- Small, erythematous macules which appear on the scalp, face, trunk, and proximal limbs, and progress over 12–14 hours to papules, clear vesicles (which are intensely itchy), and pustules. Vesicles can also occur on the palms and soles, and mucous membranes, with painful and shallow oral or genital ulcers. Vesicles appear in crops. Crusting occurs usually within 5 days, and crusts fall off after 1–2 weeks
How is chicken pox managed?
- Usually a self-limiting disease in healthy children
- Keep short nails (to avoid causing damage by scratching)
- Treating symptoms:
- Paracetamol
- Topical calamine lotion
- Chlorphenamine (avoid in certain groups, for example pregnant and breastfeeding women, and children less than 1 year of age)
- Aciclovir can be considered for an immunocompetent adult or adolescent (aged 14 years or older) who presents within 24 hours of rash onset, particularly for people with severe chickenpox or those at risk of complications
- Don’t use NSAIDs, could cause cellulitis of the lesions
What are the complications of chicken pox?
- Bacterial skin infection, most common in young children
- Lung involvement, more common in adults
- In pregnancy, severe maternal chickenpox and fetal varicella syndrome
In later pregnancy, varicella can result inneonatal chickenpox infection - In immunocompromised people, severe disseminated chickenpox with varicella pneumonia, encephalitis, hepatitis, and haemorrhagic complication
What is shingles?
Shingles (herpes zoster) is a viral infection of an individual nerve and the skin surface that is served by the nerve (dermatome). It is caused by the reactivation of the varicella-zoster virus, the virus which causes chicken pox.
How is shingles investigated?
Clinical diagnosis.
Abnormal skin sensations and pain, followed by a unilateral vesicular rash in the affected dermatome.
The location of symptoms depends on the affected nerve.
Immunocompetent people, the infection usually occurs on the thorax, with dermatomes T1 to L2 most commonly affected. In immunocompromised people, symptoms can be more widespread and affect multiple dermatomes (disseminated disease).
Rash may be atypical in older/immunocompromised
How is shingles managed?
Hospital admission if; young child, severely immunocompromised, ophthalmic involvement, widespread or systemically unwell.
Prescribe oral anti viral
Manage pain
Offer self care advice; i.e keep the rash clean, stay away from children, pregnant, immunocompromised etc.
What is a wart?
Infection of keratinocytes by HPV.
Usually found on the hands and feet, if at the base of the feet then considered a verruca.
Usually asymptomatic and will resolve spontaneously w/o treatment.
Describe the appearance of a wart.
Raised, rough, firm surfaces. May resemble a cauliflower.
May spread by direct skin-skin contact or via indirect contact.
May persist for years, resolution is faster in children.
How are warts treated?
Usually not treated unless Px insists, cosmetically unsightly, numerous.
Treat with topical salicylic acid, cryotherapy or both. Don’t tend to use cryotherapy in young children.
What is oral herpes simplex?
Viral infection causing vesicles/crusting/ulceration around the lips, cheeks or nose.
Caused often by HSV-1.
What are the signs and symptoms of oral HSV?
May present with a prodrome of fever, sore throat and lymphadenopathy.
Initial symptoms of pain, burning, tingling, and itching may precede visible lesions and typically last 6–48 hours.
Immunocompromised Px may have more serious manifestations of the virus.
How is oral HSV managed?
Non IC Px-
Analgesics for pain and fever relief
Oral acyclovir
Encourage good self care and trigger avoidance (sunlight, stress, trauma, fever)
IC Px-
Need hospital admission if unable to swallow, has serious complication, dehydrated or troublesome infection.
What is genital HSV?
Common STI caused by HSV 1 / HSV 2.
Spread via direct contact with an infected person.
How does genital HSV present at first exposure?
Multiple painful blisters on external genitalia, bursting to leave erosions and ulcers.
Usually bilateral lesions appearing 4-7 days after HSV exposure.
Px may present with dysuria, vaginal or urethral discharge, and systemic symptoms such as fever and malaise.
Primary episodes can last 20 days.
Following primary infection, the virus becomes latent in local sensory ganglia.
How does recurrent genital HSV present?
Occurs after a reactivation of HSV.
Unilateral blistering, prodromal tingling and burning symptoms hrs to days before.
Less common and less severe systemic symptoms lasting 5-10 days.
How is genital HSV investigated?
Take Hx and examination.
Take a swab for viral culture/PCR.
Screen for other STIs, HIV, pregnancy and immunosuppression.
All suspected genital herpes should be referred to the genitourinary clinic.
How is genital initial HSV managed?
Oral acyclovir 200mg five times a day started within 5 days of the start of the episode or while new lesions are forming.
This should be continued for 5-10 days, or longer if new lesions are still forming while on treatment.
How is recurrent genital HSV managed?
Self care management
Episodic antiviral treatment- 200mg 5DS for 5 days (infrequent attacks).
Suppressive oral acyclovir 400 mg twice a day for 6–12 months). This is an option if attacks are frequent (six or more attacks per year), causing psychological distress, or affecting the person’s social life.
Px with HIV may need double dose of treatment or extended period.
Refer Px with HIV, pregnancy or non resolving disease.
What is molluscum contagiosum?
Viral skin infection appearing pinkish/pearly white appearance up to 5mm in diameter. Can appear in clusters and anywhere in the body besides palm and soles.
Usually in children or immunocompromised.
Spent by direct contact or indirect through use of towels.
How is molluscum contagiosum managed?
Self limiting- resolving within 18 months.
Eczema/inflammation may appear before resolution; in which case treat with emollients if itching or Abx if infected.
What is dermatophytosis?
What are the RF?
‘Ringworm’/tinea corporis/tinea cruris (body/groin).
RF include humid environment, sweating, obesity, tight fitting clothing etc.
How is dermatophytosis diagnosed?
Clinical diagnosis- itchy, scaly skin.
Single/multiple lesions, red/pink, flat/raised annular patches with red scaly exterior and clear towards the centre.
How is dermatophytosis managed?
Advice with self care
If mild/non-extensive then topical terbinafine or imidazole.
If marked inflammation then hydrocortisone.
If severe or extensive then oral terbinafine. If not tolerated or contraindicated then itraconazole.
If still persists after topical anti fungal then identify underlying reason (i.e. non compliance, reinfection etc) send skin sample for fungal microscopy and culture.
What is candidiasis?
Yeast skin infection, occurring mainly where two surfaces of skin meet, i.e. in the folds where there is a lot of moisture.
Usually asymptomatic, unless the Px is immunocompromised or mucosa is infiltrated.
How is candidiasis diagnosed?
It is a clinical diagnosis.
Investigations are not needed, response to treatment confirms diagnosis, otherwise take a swab for MCS.
How is candidiasis managed?
1) If immunocompromised or systemic infection then hospital admission.
2) Otherwise; Topical terbinafine or imidazole.
If itchy then also give 1% hydrocortisone for 7 days. If it resolves with these then continue for 7 more days, otherwise review the diagnosis.
3) If not responsive to topical then give oral fluconazole for >16yrs, <16yrs see specialist.
What self care management would you advice a Px with candidiasis?
Hygiene
Dry thoroughly after a shower
Lose weight- if obesity is the problem
Avoid skin occlusion where possible
What is scabies?
Intensely itchy parasitic skin infestation.
Px usually infected with 10-15 mites.
Spread by direct skin contact.
Common in closed spaces with large groups i.e. schools, prisons etc.
If immunocompromised can have crusted scabies- hyper infestation with thousands to millions of mites. Need hospital.
How is scabies investigated?
Diagnosis of Hx of Px and family.
Examination of Px and family.
How is scabies treated?
Topical insecticide to be applied once and then again a week later- permethrin 5%.
For itching can take topical crotamiton.
Should encourage washing all clothes and bed sheets, also treat family members with the insecticide even if asymptomatic.
Untreated can develop a bacterial infection which can lead to impetigo, folliculitis, boils, cellulitis.
What are lice infestations?
Head lice are a parasitic infestation of hair, where the lice feed off blood from the scalp.
How are head lice diagnosed?
Detection combing.
Only active head lice is a live louse is found, despite the presence of hatched/unhatched eggs.
Should treat the Px only if they have active headlice, treat close contacts on the same day.
How are head lice managed?
Treat with either of the following;
Physical insecticide dimeticone (Hedrin).
Traditional insecticide malathion.
Wet combing with fine tooth head louse comb.
Detection combing is useful to see if the treatment is effetive.
Lifespan of lice is 1-2 days so no need to wash bedding/clothes.
