Dermatology Flashcards
What is Eczema?
Skin inflammation which is dry patchy that results from allergy
common in children which can progress to adulthood
Is eczema contagious?
autoimmune
eczema is also known as?
atopic dermatitis
Common paces eczema can be found on the skin?
Flexor surfaces like: wrist creases, elbows (inside), back of knee
Exposed surfaces: Hands, face, scalp (most common in infants) , feet
is eczema worse in the morning or night
night
What is the atopy triad?
Atopic dermatitis
Asthma
Allergic Rhinitis
What type of hypersensitivity eczema?
1
Explain eczema sensitivity?
Type 1 hypersenistivity
- Starts with environment allergey eg pollen
- Pollen picked up by APC
- presents to naive T helper cell- activates to Th2 cell
- Th2 cell stimulates B cells which produces IgE antibodies
- IgE bind to mast cells +basophils (sensitisation)
- Degranulation: histamine, leukotriene
- Inflammation causes skin to be leaky
- allows more of the allergen
- allows more water to escape=skin dry +scaly+itchy
- scrathng further damages skin layers
- skin can blister + peel
What are Emollients?
thick greasy soap substitues
Examples of thin creams for eczema?
E45
Diprobase cream
Oilatum cream
Aveeno cream
Cetraben cream
Epaderm cream
Examples of thick, greasy emollients for eczema?
50:50 ointment (50% liquid paraffin)
Hydromol ointment
Diprobase ointment
Cetraben ointment
Epaderm ointment
The purpose of steroids in ezema?
Steroids are very good for settling down the immune activity in the skin and reducing inflammation, but they do come with side effects.
Side effects of topical steroids
thinning of skin - prune to more flares, brusing, tearing,
enlarged blood vessels under the surface of the skin called _________
enlarged blood vessels under the surface of the skin called telangiectasia
The thicker the skin, the ______ the steroid required.
The thicker the skin, the stronger the steroid required.
State the steriod ladder from weakest to most potent?
State some examples?
Mild: Hydrocortisone 0.5%, 1% and 2.5%
Moderate: Eumovate (clobetasone butyrate 0.05%)
Potent: Betnovate (betamethasone 0.1%)
Very potent: Dermovate (clobetasol propionate 0.05%)
Opportunistic bacterial infection of the skin is common in eczema.The breakdown in the skin’s protective barrier allows an entry point for infective organisms. The most common organism is ___________ _____
staphylococcus aureus
WHat is the treatment for bacterial infection in eczema?
flucloxacillin.
More severe cases may require admission and intravenous antibiotics.
What is Eczema Herpeticum?
What organism causes this?
Eczema herpeticum is a viral skin infection in patients with eczema
caused by the herpes simplex virus (HSV) or varicella zoster virus (VZV).
Mx for Eczema?
Allergy mediated inflammation- avoid overheating, dressing in soft fabric, manage stress
Dry skin- frequen moisturisation after warm bath
Itching- short finger nails, anti histamines
What is HSP
Henoch-Schonlein Purpura (HSP)
Definition of HSP?
is an IgA vasculitis that presents with a purpuric rash affecting the lower limbs and buttocks in children. Inflammation occurs in the affected organs due to IgA deposits in the blood vessels.
HPS affectsskin, kidneys and gastro-intestinal tract
TRUE OR FALSE
TRUE
HPS is often triggered by?
upper airway infection or gastroenteritis.
Who is HSP common in?
most common in children under the age of 10 years.
HSP
The four classic features are:
Purpura (100%),
Joint pain (75%),
Abdominal pain (50%)
Renal involvement (50%) - IgA nephritis
What causes the HSP rash?
The rash is caused by inflammation and leaking of blood from small blood vessels under the skin, forming purpura. Purpura are red-purple lumps under the skin containing blood.
What is purpura?
What condition is purpura?
They are red-purple in colour and are palpable under the skin. Typically they start on the legs and spread to the buttocks. They can also affect the trunk and arms. In severe cases, skin ulceration and necrosis can develop.
Purpura are seen in practically 100% of patients with HSP
in 75% patients HSP develops into
arthralgia or arthritis
mostly affecting the knees and ankles.
The joints can become swollen and painful, with a reduced range of movement.
HSP- abdominal pain in severe cases can lead to?
gastrointestinal haemorrhage, intussusception and bowel infarction.
HSP affects the kidneys in around 50% of patients, causing an IgA nephritis. This is sometimes referred to as ____ _______. This can lead to microscopic or macroscopic _________ and ________
HSP affects the kidneys in around 50% of patients, causing an IgA nephritis. This is sometimes referred to as HSP nephritis. This can lead to microscopic or macroscopic haematuria and proteinuria
How do you diagnose HPS?
Full blood count and blood film for thrombocytopenia, sepsis and leukaemia
Renal profile for kidney involvement
Serum albumin for nephrotic syndrome
CRP for sepsis
Blood cultures for sepsis
Urine dipstick for proteinuria
Urine protein:creatinine ratio to quantify the proteinuria
Blood pressure for hypertension
What is EULAR/PRINTO/PRES criteria ?
There are many different sets of criteria for diagnosing HSP, the most recent being the EULAR/PRINTO/PRES criteria from 2010. This requires the patient to have palpable purpura (not petichiae) + at least one of:
- Diffuse abdominal pain
- Arthritis or arthralgia
- IgA deposits on histology (biopsy)
- Proteinuria or haematuria
Differentials for HSP
The most important initial step is to exclude other serious pathology, such as meningococcal septicaemia and leukaemia. Idiopathic thrombocytopenic purpura and haemolytic uraemic syndrome are also differentials for a non-blanching rash
Management for HSP
Management is supportive, with simple analgesia, rest and proper hydration.
Prognosis for HSP
Abdominal pain usually settles within a few days. Patients without kidney involvement can expect to fully recover within 4 to 6 weeks. A third of patients have a recurrence of the disease within 6 months. A very small proportion of patients will develop end stage renal failure.
WHat is ITP?
Idiopathic thrombocytopenic purpura (ITP) is a condition characterised by idiopathic (spontaneous) thrombocytopenia (low platelet count) causing a purpuric rash (non-blanching rash).
Cause of ITP?
ITP is caused by a type II hypersensitivity reaction. It is caused by the production of antibodies that target and destroy platelets. This can happen spontaneously, or it can be triggered by something, such as a viral infection.
Presentation of ITP
diopathic thrombocytopenic purpura usually present in children under 10 years old. Often there is a history of a recent viral illness. The onset of symptoms occurs over 24 – 48 hours:
- Bleeding, for example from the gums, epistaxis or menorrhagia
- Bruising
- Petechial or purpuric rash, caused by bleeding under the skin
Diagnosis of ITP?
The condition can be confirmed by doing an urgent full blood count for the platelet count. Other values on the FBC should be normal. Other causes of a low platelet count should be excluded, for example heparin induced thrombocytopenia and leukaemia.
Tx for ITP?
Treatment may be required if the patient is actively bleeding or severe thrombocytopenia (platelets below 10):
- Prednisolone
- IV immunoglobulins
- Blood transfusions if required
- Platelet transfusions only work temporarily
- Platelet transfusions only work temporarily because the antibodies against platelets will begin destroying the transfused platelets as soon as they are infused.
ITP
WHat are some key education and advice?
- Avoid contact sports
- Avoid intramuscular injections and procedures such as lumbar punctures
- Avoid NSAIDs, aspirin and blood thinning medications
- Advice on managing nosebleeds
- Seek help after any injury that may cause internal bleeding, for example car accidents or head injuries
Complications of ITP
- Chronic ITP
- Anaemia
- Intracranial and subarachnoid haemorrhage
- Gastrointestinal bleeding
WHat is psorasis?
Psoriasis is a chronic autoimmune condition that causes recurrent symptoms of psoriatic skin lesions.
Causes of psoriasis?
There is a large variation in how severely patients are affected with psoriasis. There appears to be a genetic component but no clear genetic inheritance has been established. Around a third of patients have a first degree relative with psoriasis. The symptoms start in childhood in a third of patients.
Patches of psoriasis are ____ _____ ____, faintly _______ skin lesions that appear in ______ and ______ plaques, commonly over the _______ ______ of the ________ and ________and on the scalp
Patches of psoriasis are dry, flaky, scaly, faintly erythematous skin lesions that appear in raised and rough plaques, commonly over the extensor surfaces of the elbows and knees and on the scalp
What are the different types of psoriasis?
Plaque psoriasis
Guttate psoriasis
Pustular psoriasis
Erythrodermic psoriasis
NAme rare severe form of psoriasis?
Pustular psoriasis
Erythrodermic psoriasis
Most common form of psoriasis?
Plaque psoriasis
Which type of psoriasis is triggered by a streptococcal throat infection, stress or medications.
Guttate psoriasis
Presentation for psoriasis?
n children the distribution and presentation of psoriasis may differ from adults. Guttate psoriasis is more common in children, often triggered by a throat infection. Plaques of psoriasis are likely to be smaller, softer and less prominent.
There are a few specific signs suggestive of psoriasis:
- Auspitz sign refers to small points of bleeding when plaques are scraped off
- Koebner phenomenon refers to the development of psoriatic lesions to areas of skin affected by trauma
- Residual pigmentation of the skin after the lesions resolve
Management for psorisis?
The treatment options include:
- Topical steroids
- Topical vitamin D analogues (calcipotriol)
- Topical dithranol
- Topical calcineurin inhibitors (tacrolimus) are usually only used in adults
- Phototherapy with narrow band ultraviolet B light is particularly useful in extensive guttate psoriasis
There are two products that contain both a potent steroid and vitamin D analogue that are commonly prescribed for psorasis and worth being aware of. These not licensed in children and will be guided by a specialist.
What are they?
- Dovobet
- Enstilar
Associations of psoriasis?
Nail psoriasis
Psoriatic arthritis
depression and anxiety
obesity
hyperlipidaemia
hypertension
type 2 diabetes.
WHat is Erythema nodosum?
Erythema nodosum is a condition where red lumps appear across the patient’s shins. Erythema means red and nodosum directly translates from Latin as “knots”, referring to lumps.
Causes of erythema nodosum?
It is caused by inflammation of the subcutaneous fat on the shins. Inflammation of fat is called panniculitis. It is caused by a hypersensitivity reaction. In around half of patients there is no identifiable cause. It is associated with a number of triggers and underlying conditions.
Associations with erythema nodosum?
Erythema nodosum is caused by a hypersensitivity reaction, and there is often an identifiable cause:
- Streptococcal throat infections
- Gastroenteritis
- Mycoplasma pneumoniae
- Tuberculosis
- Pregnancy
- Medications, such as the oral contraceptive pill and NSAIDs
It is also associated with chronic diseases:
- Inflammatory bowel disease
- Sarcoidosis
- Lymphoma
- Leukaemia
Erythema nodosum often indicates ________ ______ ________ or _________ in exams.
Erythema nodosum often indicates inflammatory bowel disease or sarcoidosis in exams.
Presentation
Erythema nodosum
Erythema nodosum presents with red, inflamed, subcutaneous nodules across both shins. The nodules are raised and can be painful and tender. Over time the nodules settle and appears as bruises.
When you suspect someone has erythema nodosum it is important to look for signs and symptoms of potential triggers and underlying medical conditions.
Investigations Erythema nodosum
The diagnosis of erythema nodosum is based on the clinical presentation. Investigations can be helpful in assessing the underlying cause:
- Inflammatory markers (CRP and ESR)
- Throat swab for streptococcal infection
- Chest xray can help identify mycoplasma, tuberculosis, sarcoidosis and lymphoma
- Stool microscopy and culture for campylobacter and salmonella
- Faecal calprotectin for inflammatory bowel disease
Mx for erythema nodosum?
Management mainly involves investigating for an underlying condition and treating the underlying cause.
Erythema nodosum is managed conservatively with rest and analgesia. Steroids may be used to help settle the inflammation.
Most cases of eythema nodosum will fully resolve within _ _____, however it can last longer.
Most cases of eythema nodosum will fully resolve within 6 weeks, however it can last longer.
WHat is acne vulgaris?
Acne vulgaris (acne) is an extremely common condition, often affecting people during puberty and adolescence. Most people are affected at some point during their lives, and symptoms can range from mild to severe.
patho of acne vulgaris
Acne is caused by chronic inflammation, with or without localised infection, in pockets within the skin known as the pilosebaceous unit. The pilosebaceous units are the tiny dimples in the skin that contain the hair follicles and sebaceous glands. The sebaceous glands produce the natural skin oils and a waxy substance known as sebum.
Acne results from increased production of sebum, trapping of keratin (dead skin cells) and blockage of the pilosebaceous unit. This leads to swelling and inflammation in the pilosebaceous unit. Androgenic hormones increase the production of sebum, which is why acne is exacerbated by puberty and improves with anti-androgenic hormonal contraception. Swollen and inflamed units are called comedones.
Which bacteria plays an important part in acne?
Propionibacterium acnes bacteria
colonises the skin.
It is thought that excessive growth of this bacteria can exacerbate acne. Many of the treatments of acne aim to reduce these bacteria.
Presentation of acne
There is significant variation in the severity of acne. It presents with red, inflamed and sore “spots” on the skin, typically distributed across the face, upper chest and upper back.
Management for acne
Treatment is initiated in a stepwise fashion based on the severity and response to treatment:
- No treatment may be acceptable if mild
- Topical benzoyl peroxide reduces inflammation, helps unblock the skin and is toxic to the P. acnes bacteria
- Topical retinoids (chemicals related to vitamin A) slow the production of sebum (women of childbearing age need effective contraception)
- Topical antibiotics such as clindamycin (prescribed with benzoyl peroxide to reduce bacterial resistance)
- Oral antibiotics such as lymecycline
- Oral contraceptive pill can help female patients stabilise their hormones and slow the production of sebum
What is a last line option for severe acne
Oral retinoids for severe acne (i.e. isotretinoin) is an effective last-line option, although it is only prescribed by a specialist after other methods fail. This needs careful follow-up and monitoring and reliable contraception in females. Retinoids are highly teratogenic.
What is the most effective combined contraceptive pill for acne?
S/E
Co-cyprindiol (Dianette) is the most effective combined contraceptive pill for acne due to it’s anti-androgen effects.
It has a higher risk of thromboembolism, so treatment is usually discontinued once acne is controlled and it is not prescribed long term.