Dermatology Flashcards
(41 cards)
What is Pityriasis Rosea?
Pityriasis rosea describes an acute, self-limiting rash which tends to affect young adults.
Herald patch followed 1-2 weeks later by multiple erythematous, slightly raised oval lesions with a fine scale confined to the outer aspects of the lesions.
May follow a characteristic distribution with the longitudinal diameters of the oval lesions running parallel to the line of Langer. This may produce a ‘fir-tree’ appearance.
Self-limiting, resolves after around 6 weeks.
Mx for Actinic Keratosis?
AK is a common premalignant skin condition.
- Small, crusty or scaly, lesions
- May be pink, red, brown or the same colour as the skin
- Typically on sun-exposed areas e.g. temples of head
- Sun avoidance, sun cream
- Fluorouracil cream: typically a 2 to 3 week course.
- Topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
- Topical imiquimod: trials have shown good efficacy
- cryotherapy
- curettage and cautery
Feature of BCC?
BCC lesions are also known as rodent ulcers and are characterised by slow-growth and local invasion. Metastases are extremely rare. BCC is the most common type of cancer in the Western world.
- Sun-exposed sites, especially the head and neck account for the majority of lesions
- initially a pearly, flesh-coloured papule with telangiectasia
- may later ulcerate leaving a central ‘crater’
- Surgical removal
- Curettage
- Cryotherapy
- Topical cream: imiquimod, fluorouracil
- Radiotherapy
Types of Psoriasis?
- Plaque psoriasis: the most common sub-type resulting in the typical well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp.
- Flexural psoriasis: in contrast to plaque psoriasis the skin is smooth.
- Guttate psoriasis: transient psoriatic rash frequently triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body.
- Pustular psoriasis: commonly occurs on the palms and soles.
Pompholyx?
AKA Dyshidrotic eczema, primarily affects hands and feet causing itchy vesicles.
Pompholyx is a type of eczema which affects both the hands (cheiropompholyx) and the feet (pedopompholyx). It is also known as dyshidrotic eczema.
Pompholyx eczema may be precipitated by humidity (e.g. sweating) and high temperatures.
Features:
- small blisters on the palms and soles
- pruritic
- often intensely itchy
- sometimes burning sensation
- once blisters burst skin may become dry and crack
Management
cool compresses
emollients
topical steroids
Polymorphic eruption of pregnancy?
A benign dermatological condition that occurs in late pregnancy. It typically presents with intensely itchy, polymorphic lesions including erythematous papules, vesicles or plaques. The rash often starts on the abdomen, particularly within stretch marks (striae), and can spread to the thighs and buttocks but rarely involves the face or mucous membranes.
Management depends on severity: emollients, mild potency topical steroids and oral steroids may be used.
USUALLY SPARES UMBILICUS.
Pemphigoid Gestationis?
- Pruritic blistering lesions
often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms. - Usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy.
-Oral corticosteroids are usually required.
Features of HHT?
AKA Osler-Weber-Rendu syndrome, HHT is an autosomal dominant condition characterised by multiple telangiectasia over the skin and mucous membranes.
- Epistaxis : spontaneous, recurrent nosebleeds.
- Telangiectases: multiple at characteristic sites (lips, oral cavity, fingers, nose).
- Visceral lesions: for example gastrointestinal telangiectasia, pulmonary arteriovenous malformations (AVM), hepatic AVM, cerebral AVM, spinal AVM.
- Family history: a first-degree relative with HHT
Lichen Scelrosus?
It is an inflammatory condition that usually affects the genitalia and is more common in elderly females.
- White patches that may scar
- Itch is prominent
- May result in pain during intercourse or urination
Management: Topical steroids and emollients
Seborrhoeic keratoses?
Seborrhoeic keratoses are benign epidermal skin lesions seen in older people.
- Large variation in colour from flesh to light-brown to black.
- Have a ‘stuck-on’ appearance
- Keratotic plugs may be seen on the surface.
Mx:
Reassurance about the benign nature of the lesion is an option.
Options for removal include curettage, cryosurgery and shave biopsy.
Causes of Erythema Nodosum?
- Inflammation of subcutaneous fat
typically causes tender, erythematous, nodular lesions. - Usually occurs over shins, may also occur elsewhere (e.g. forearms, thighs).
- Usually resolves within 6 weeks
lesions heal without scarring.
Causes:
1. Infection
- streptococci
- tuberculosis
- brucellosis
- systemic disease
- sarcoidosis
- inflammatory bowel disease
- Behcet’s - Malignancy/lymphoma
- Drugs
- penicillins
- sulphonamides
- COCP - Pregnancy
Pemphigus vulgaris features?
Pemphigus vulgaris is an autoimmune disease caused by antibodies directed against desmoglein 3, a cadherin-type epithelial cell adhesion molecule.
Mucosal ulceration is common and often the presenting symptom. Oral involvement is seen in 50-70% of patients.
- Skin blistering: FLACCID, easily ruptured vesicles and bullae. Lesions are typically painful but not itchy. These may develop months after the initial mucosal symptoms.
Mx:
Steroids are first-line
Immunosuppressants
Guttate Psoriasis?
Guttate psoriasis is more common in children and adolescents. It may be precipitated by a streptococcal infection 2-4 weeks prior to the lesions appearing.
- Tear drop papules on the trunk and limbs.
- pink, scaly patches or plaques of psoriasis
- Tends to be acute onset over days
Mx:
- Most cases resolve spontaneously within 2-3 months
- Topical agents as per psoriasis
UVB phototherapy
-Tonsillectomy may be necessary with recurrent episodes
Necrobiosis lipoidica?
- Shiny, painless areas of yellow/red skin typically on the shin of DIABETICS.
- often associated with telangiectasia
Erythema Multiforme trigger?
Erythema multiforme is a hypersensitivity reaction that is most commonly triggered by infections.
- Target lesions
- Initially seen on the back of the hands / feet before spreading to the torso
- upper limbs are more commonly affected than the lower limbs
- pruritus is occasionally seen and is usually mild
- Viruses: herpes simplex virus (the most common cause), Orf*
- idiopathic
- bacteria: Mycoplasma, Streptococcus
- Drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
connective tissue disease e.g. Systemic lupus erythematosus - Sarcoidosis
- Malignancy
Mx for scabies?
- Permethrin 5% is first-line
- Malathion 0.5% is second-line
pruritus persists for up to 4-6 weeks post eradication
All household and close physical contacts should be treated at the same time, even if asymptomatic.
Launder, iron or tumble dry clothing, bedding, towels, etc., on the first day of treatment to kill off mites.
- Apply the insecticide cream or liquid to cool, dry skin.
- Pay close attention to areas between fingers and toes, under nails, armpit area, creases of the skin such as at the wrist and elbow
- Allow to dry and leave on the skin for 8-12 hours for permethrin, or for 24 hours for malathion, before washing off
- Reapply if insecticide is removed during the treatment period, e.g. If wash hands, change nappy, etc
- Repeat treatment 7 days later
Which medication is known to exacerbate plaque psoriasis?
Psoriasis may be exacerbated by a variety of causes. With respect to drugs, the most common suspects are lithium and BETA BLOCKERS. Other agents include antimalarials, ACE inhibitors and non-steroidal anti-inflammatories
Mx for vitiligo?
- Loss of melanocytes and consequent depigmentation of the skin.
Associated conditions:
- Type 1 diabetes mellitus
- Addison’s disease
- Autoimmune thyroid disorders
- Pernicious anaemia
- Alopecia areata
Mx:
- Sunblock for affected areas of skin
- Topical corticosteroids may reverse the changes if applied early
- There may also be a role for topical tacrolimus and phototherapy.
Features of zinc deficiency?
Zinc deficiency causes a characteristic skin rash (mainly affecting the intertriginous and perioral areas), alopecia, taste impairment, glucose intolerance, and diarrhoea.
- Acrodermatitis: red, crusted lesions
- Alopecia
- Short stature
- Hypogonadism
- Hepatosplenomegaly
- Geophagia (ingesting clay/soil)
- Cognitive impairment
Features of pyogenic granuloma?
Pyogenic granuloma is a relatively common benign skin lesion. The name is confusing as they are neither true granulomas nor pyogenic in nature.
- Most common sites are head/neck, upper trunk and hands. Lesions in the oral mucosa are common in pregnancy.
- Initially small red/brown spot
rapidly progress within days to weeks forming raised, red/brown lesions which are often spherical in shape - The lesions may bleed profusely or ulcerate. hey can develop rapidly over a few weeks and tend to bleed easily because they contain many blood vessels.
Features of yellow nail syndrome?
Slowing of the nail growth leads to the characteristic thickened and discoloured nails seen in yellow nail syndrome.
Associations:
1. Congenital lymphoedema
2. Pleural effusions
3. Bronchiectasis
4. Chronic sinus infections
Pyoderma Gangrenosum associated with which conditions?
Pyoderma gangrenosum is a rare, non-infectious, inflammatory disorder. It is an uncommon cause of very painful skin ulceration. It may affect any part of the skin, but the lower legs are the most common site.
Pyoderma gangrenosum is classified as a neutrophilic dermatosis. Neutrophilic dermatoses are skin conditions characterised by dense infiltration of neutrophils in the affected tissue and this is often seen on biopsy.
- Idiopathic in 50%
- IBD
- RA, SLE
- Myeloproliferative disorders
lymphoma
myeloid leukaemias - Monoclonal gammopathy (IgA)
- ranulomatosis with polyangiitis
- Primary biliary cirrhosis
- Typically on the lower limb, often at the site of a minor injury, this is known as pathergy
- Usually starts quite suddenly
small pustule, red bump or blood-blister - The skin then breaks down resulting in an ulcer which is often painful
the edge of the ulcer is often described as purple, violaceous and undermined. - The ulcer itself may be deep and necrotic
- Fever, myalgia
Mx:
The potential for rapid progression is high in most patients and most doctors advocate oral steroids as first-line treatment.
other immunosuppressive therapy, for example, ciclosporin and infliximab, have a role in difficult cases
Cherry Haemangioma?
Cherry haemangiomas are benign skin lesions which contain an abnormal proliferation of capillaries. They are more common with advancing age and affect men and women equally.
Management for Chronic plaque psoriasis?
Regular emollients may help to reduce scale loss and reduce pruritus.
- Potent corticosteroid applied once daily plus vitamin D analogue applied once daily.
- should be applied separately, one in the morning and the other in the evening.
- for up to 4 weeks as initial treatment
second-line: if no improvement after 8 weeks then offer:
2. Vitamin D analogue twice daily
Third-line: if no improvement after 8-12 weeks then offer either:
3. A potent corticosteroid applied twice daily for up to 4 weeks or
a coal tar preparation applied once or twice daily.
- Short-acting dithranol can also be used
