Dermatology Flashcards
Eczema
A chronic atopic condition caused by defects in the normal continuity of the skin barrier, leading to gaps which allow irritants, microbes and allergens to enter, creating an immune response and leading to inflammation.
Environmental Triggers for Eczema
changes in temperature, certain dietary products, washing powders, cleaning products and emotional events/stress.
Symptoms of Eczema
Usually in infancy - Dry, red, itchy skin with sore patches over the flexor surfaces (elbows, knees) and face and neck - Often episodic with flares
Management of Eczema
For maintenance, emollients e.g. E45, Diprobase should be used as often as possible, especially after washing and before bed which help create an artificial barrier over the skin
How should Eczema flare ups be treated?
- Flare ups can be treated with thicker emollients such as Cetraben ointment or topical steroids such as Hydrocortisone and Betnovate (beclomethasone) which help keep moisture locked in overnight - Other specialist treatments include topical tacrolimus, oral corticosteroids and methotrexate.
Stevens-Johnson Syndrome
A disproportional immune response causing epidermal necrosis resulting in blistering and shedding of the top layer of the skin - less than 10% of body surface area affected
Aetiology of Stevens-Johnson Syndrome is mainly down to 2 things - which are?
Medications + Infections
Medication causes of Stevens-Johnson Syndrome
- Anti epileptics - Antibiotics - Allopurinol - NSAIDs
Infectious causes of Stevens-Johnson Syndrome
- Herpes simplex - Mycoplasma pneumonia - Cytomegalovirus - HIV
Symptoms of Stevens-Johnson Syndrome
- Some cases will be mild whilst others will be severe and potentially fatal
- Non-specific symptoms initially with fever, cough, sore throat, sore mouth, sore eyes and itchy skin
- Purple/red rash which spreads across the skin and blisters, this then breaks away and leaves the raw tissue underneath
- Pain, blistering and shedding can also happen to the lips and mucous membranes
- Inflammation and ulceration of the eyes can also happen - It can also affect the urinary tract, lungs and internal organs
Managment of Stevens-Johnson Syndrome
Medical emergency: supportive care is essential - Steroids, immunoglobulins and immunosuppressant medications can all be given with specialist guidance
Complications of Stevens-Johnson Syndrome
Secondary infection such as cellulitis, sepsis - Permanent skin damage
What is allergic rhinitis?
Allergic rhinitis is an IgE-mediated hypersensitivity reaction of the nasal mucosa to allergens, leading to symptoms such as sneezing, nasal congestion, rhinorrhea, and itchy eyes or nose.
What are the two types of allergic rhinitis?
Seasonal allergic rhinitis (hay fever) – occurs during specific pollen seasons.
Perennial allergic rhinitis – occurs year-round due to allergens like dust mites, pet dander, or mold.
What are the common allergens causing allergic rhinitis?
Pollen
Dust mites
Animal dander
Mold spores
What is the pathophysiology of allergic rhinitis?
Allergens trigger IgE production, leading to mast cell activation and the release of histamine, leukotrienes, and prostaglandins. This causes inflammation and typical allergy symptoms.
List the risk factors for allergic rhinitis.
Family history of atopy (e.g., asthma, eczema)
Exposure to allergens
Urban living
Presence of other atopic conditions
What complications can arise from untreated allergic rhinitis?
Chronic sinusitis
Nasal polyps
Otitis media with effusion
Sleep disturbances
Allergic rhinitis is mediated by __________ and involves hypersensitivity reactions.
IgE
__________ is a major risk factor for developing allergic rhinitis, especially in individuals with asthma or eczema.
Family history of atopy
Common nasal symptoms of allergic rhinitis include __________, __________, and __________.
Sneezing, nasal congestion, rhinorrhea
The __________ test is used to confirm allergen-specific IgE levels in allergic rhinitis.
Skin prick
Nasal corticosteroids like __________ are first-line treatments for moderate to severe allergic rhinitis.
Fluticasone
Which of the following is NOT a common symptom of allergic rhinitis?
A. Sneezing
B. Nasal congestion
C. Chest pain
D. Rhinorrhea
C. Chest pain
Which medication is most effective for long-term management of allergic rhinitis?
A. Antihistamines
B. Nasal corticosteroids
C. Decongestants
D. Leukotriene receptor antagonists
B. Nasal corticosteroids
Scenario: A 10-year-old boy presents with sneezing, nasal congestion, and itchy eyes during the spring. His symptoms improve when he stays indoors.
Q: What is the likely diagnosis, and what management would you recommend?
Likely diagnosis: Seasonal allergic rhinitis (hay fever).
Management: Allergen avoidance, antihistamines (e.g., cetirizine), and intranasal corticosteroids (e.g., fluticasone).
Scenario: A child with year-round nasal congestion and recurrent ear infections is found to have dust mites in their home.
Q: What would you recommend to address the allergic rhinitis and prevent complications?
Allergen control: Dust mite covers, frequent cleaning, and dehumidifiers.
Medical treatment: Intranasal corticosteroids and antihistamines.
Arrange the steps in the management of allergic rhinitis:
A. Identify triggers using history and allergy testing
B. Implement allergen avoidance measures
C. Initiate pharmacotherapy (e.g., antihistamines, nasal corticosteroids)
D. Consider immunotherapy for refractory cases
A → B → C → D
What is an appropriate treatment for Nasal congestion
Intranasal corticosteroids
What is an appropriate treatment for Sneezing and itching
Oral antihistamines
What is an appropriate treatment for Severe or refractory cases of allergic rhinitis
Immunotherapy
What is an appropriate treatment for Temporary relief of nasal congestion
Decongestants
What are the pros and cons of immunotherapy for allergic rhinitis?
Pros:
Reduces symptoms and medication use
Long-term benefits
Can prevent progression to asthma
Cons:
Time-intensive (requires regular injections or tablets)
Risk of allergic reactions, including anaphylaxis
Why is allergen avoidance important in managing allergic rhinitis, and what challenges might patients face in implementing it?
Importance: Reduces exposure to triggers, minimizing symptoms and medication dependence.
Challenges: Practical difficulties in avoiding ubiquitous allergens like pollen and dust mites, especially in urban environments.
Urticaria
- Also known as hives, these are small itchy lumps which appear on the skin and may be associated with angioedema.
Pathophysiology of Urticaria
- Release of histamine and other pro-inflammatory chemicals by mast cells in the skin - These may be part of an allergic reaction in acute urticaria or an autoimmune reaction in chronic idiopathic urticaria
Aetiology of Urticaria
Allergies to food, medications or animals
Contact with chemicals, latex or stinging nettles
Medications
Viral infections
Insect bites
Chronic Urticaria
An autoimmune condition where autoantibodies target mast cells and trigger them to release histamines and other chemicals
Management of Urticaria
Antihistamines - Fexofenadine is the antihistamine of choice for chronic urticaria
Oral steroids may be given for flare ups
Omalizumab which targets IgE
___% of Anaphylaxis cases are caused by a food allergy with an IgE mediated response causing significant respiratory/cardiovascular compromise.
85
Name some other causes of Anaphylaxis
drugs, insect stings, latex, exercise and idiopathic
Most cases of Anaphylaxis occur in _____
children under 5
Most fatal cases of Anaphylaxis occur in ___
adolescence.
Acute managment of Anaphylaxis
Acute management is early administration of adrenaline and long term management involves a detailed plan for allergy avoidance and the presence of adrenaline auto-injectors.
What are the two main types of birthmarks?
Pigmented birthmarks (e.g., café-au-lait spots, congenital melanocytic nevi)
Vascular birthmarks (e.g., hemangiomas, port-wine stains)
What causes vascular birthmarks?
Vascular birthmarks are caused by abnormal development or growth of blood vessels in the skin.
What are café-au-lait spots, and what condition are they associated with when numerous?
Café-au-lait spots are flat, pigmented birthmarks that may be associated with neurofibromatosis type 1 (NF1) if there are six or more, each over 5 mm in children or 15 mm in adults.
What is a hemangioma, and how does it typically progress?
A hemangioma is a benign vascular tumor that often grows rapidly during the first year of life and then slowly regresses over time.
What are port-wine stains, and which syndrome are they associated with?
Port-wine stains are flat, red-purple vascular birthmarks associated with Sturge-Weber syndrome when located on the face, particularly in the distribution of the trigeminal nerve.
__________ birthmarks result from overgrowth of melanocytes in the skin.
Pigmented.
A __________ is a benign vascular tumor commonly seen in infants, often resolving without treatment.
Hemangioma
Port-wine stains are commonly seen in the __________ region and may indicate Sturge-Weber syndrome.
Facial
Café-au-lait spots are significant if there are __________ or more large lesions, suggesting neurofibromatosis.
6
Mongolian spots are typically found on the __________ and are more common in __________ infants.
Lower back/buttocks; darker-skinned
Which birthmark is most likely to fade with age?
A. Port-wine stain
B. Hemangioma
C. Café-au-lait spot
D. Congenital melanocytic nevus
B. Hemangioma
Which condition is associated with multiple café-au-lait spots?
A. Sturge-Weber syndrome
B. Neurofibromatosis type 1
C. Klippel-Trenaunay syndrome
D. Tuberous sclerosis
B. Neurofibromatosis type 1
What is the most common location for Mongolian spots?
A. Face
B. Abdomen
C. Lower back and buttocks
D. Hands and feet
C. Lower back and buttocks
Scenario: A 3-month-old infant presents with a bright red, raised lesion on the scalp. The lesion has been increasing in size.
Q: What is the likely diagnosis, and how would you manage it?
Likely diagnosis: Hemangioma. Management: Observation, as most hemangiomas regress spontaneously. Consider beta-blockers (e.g., propranolol) for large or complicated lesions.
Scenario: A newborn is found to have a large, flat, purple birthmark over the right side of their face.
Q: What is the birthmark, and what syndrome should be ruled out?
The birthmark is a port-wine stain. Sturge-Weber syndrome should be ruled out, particularly if the stain is in the trigeminal nerve distribution.
Place these steps in the evaluation of a significant café-au-lait spot in order:
A. Count the number of spots
B. Measure the size of each spot
C. Assess for family history of neurofibromatosis
D. Refer for genetic testing if criteria for NF1 are met
A → B → C → D
Cafe au lait spots are associated with
Associated with NF1 if numerous
Characteristic of Port Wine Stain
Flat, red-purple, linked to Sturge-Weber syndrome
Characteristic of Hemangioma
Benign vascular tumor, regresses over time
Characteristic of Mongolian Spot
Blue-grey pigmentation, common in darker-skinned infants
What are the pros and cons of treating vascular birthmarks like port-wine stains?
Pros:
Improves cosmetic appearance
Prevents potential complications like hypertrophy or bleeding
Cons:
Treatment (e.g., laser therapy) can be costly and require multiple sessions
May not completely remove the birthmark
Why is it important to distinguish between harmless birthmarks and those associated with syndromes?
Early identification of syndromic associations (e.g., NF1, Sturge-Weber) enables prompt diagnosis, monitoring for complications, and appropriate management or genetic counseling.
Describe the typical appearance and location of Mongolian spots.
Mongolian spots are blue-grey patches commonly found on the lower back and buttocks of darker-skinned infants. They are harmless and usually fade by early childhood.
Nappy Rash
Contact dermatitis in the nappy area, normally caused by friction between the skin and nappy and contact with the urine and faeces. Breakdown of skin and the warm moist environment can lead to candida (fungus) or
bacteria infection (staphylococcus/streptococcus)
Nappy Rash is most common in what age group?
9-12 months of age
Risk factors for Nappy Rash
- Delayed changing of nappies
- Irritant soap products and vigorous cleaning
- Diarrhoea
- Oral antibiotics predispose to candida
- Preterm infants
Symptoms of Nappy Rash
- Sore, red, inflamed skin in the nappy areas
- No rash on the creases of the groin
- The rash may be itchy and the infant may be distressed
- Severe and long standing rash can lead to erosion and ulceratio
Differentiating Candida vs Nappy Rash - what do you look for?
Rash extending into the skin folds
Large red macules
Well demarcated scaly border
Circular pattern to the rash spreading outwards, similar to ringworm
Satellite lesions - small, similar patches of rash near the main rash
Management of Nappy Rash
Switching to highly absorbent nappies
Change the nappy and clean the skin as soon as possible after wetting or soiling
Use water or gentle alcohol free products
Ensure the nappy area is dry before replacing the nappy
Maximise time not wearing a nappy
Infection requires antifungal/antibiotic cream
Non-Blanching Rashes caused by
Caused by bleeding under the skin
Petechiae
Petechiae are small, non blanching, red spots on the skin caused by burst capillaries
Purpura
Purpura are larger, non-blanching, red-purple macules or papules caused by leaking of blood from vessels under the skin
Any child with Non-Blanching Rashes needs ____
immediate investigation due to the risk of meningococcal sepsis.
Differentials for Non-Blanching Rashes
Meningococcal sepitcaemia, HSP, ITP, Leukaemias, HUS, Mechanical, Traumatic, Viral illness can often cause rashes
Symptoms of Meningococcal Septicaemia
feverish, unwell child which requires immediate antibiotic management due to significant morbidity/mortality
Symptoms of HSP
purpuric rash on the legs and buttocks and may have associated abdominal or joint pain
Symptoms of ITP
: rash which develops over several days in an otherwise unwell child
Symptoms of Leukaemias
gradual development of petechiae with other signs such as anaemia, lymphadenopathy and hepatosplenomegaly
Symptoms of HUS
Presents in a child with recent diarrhoea alongside oliguria and signs of anaemia.
Symptoms of Mechanical cause of Non-Blanching Rashes
Strong coughing, vomiting or breath holding can product petechiae above the neck and most prominently around the eyes
Symptoms of Traumatic cause of Non-Blanching Rashes
Tight pressure on the skin e.g NAI can lead to traumatic petechiae
Ix for Non-Blanching Rashes
FBC, U+e, CRP, ESR, Blood cultures, Meningococcal PCR, LP, Blood pressure and urine dipstick
Macules
flat, nonpalpable lesions, <10mm
Papules
elevated lesions, <10mm
Plaques
palpable lesions, >10mm, elevated/depressed compared to skin
Vesicles
small, clear, fluid-filled blisters
