Dermatitis Flashcards
What is eczema herpeticum?
complication of atopic dermatitis/eczema.
disseminated viral infection characterised by fever and clusters of itchy blisters or punched-out erosions.
What is the cause of eczema herpeticum?
Most cases of eczema herpeticum are due to Herpes simplex type 1 or 2. usually arises during a first episode of infection with Herpes simplex (primary herpes).
more commonly seen in infants and children with atopic dermatitis.
better called Kaposi varicelliform eruption when a breakdown of the skin barrier is not due to eczema.
Common site for eczema herpeticum?
most often seen on face and neck
Eczema herpeticum classical appearance
clusters of itchy and painful blisters.
Monomorphic
Blood stained
Filled with pus
Umbilication
Sores formation
White scars may persist
patient with known atopic dermatitis presents with an acute eruption of painful, monomorphic clustered vesicles associated with fever and malaise. What is the diagnosis?
Eczema herpeticum
What is the treatment of eczema herpeticum?
dermatological emergencies
Oral aciclovir 400–800 mg 5 times daily, or, if available, valaciclovir 1 g twice daily, for 10–14 days or until lesions heal
Tide water mark dermatitis
What is Hertoghe’s sign
Also known as Queen Anne’s sign
thinning or loss of the outer third of the eyebrows,
Hertoghe Sign is a classical sign of which diseases?
hypothyroidism or atopic dermatitis
can also be detected in lepromatous leprosy
What is atopic dermatitis?
also called atopic eczema
the most common inflammatory skin disease worldwide,
presents as generalised
skin dryness, itch, and rash.
Approximately ……………. percent of children affected develop
it before the age of 6 years.
Eighty percent
20 percent starts in infancy.
Footnote: prevalence
in young adults up to 26 years of age is still 5–15%.
clinical features of atopic dermatitis?
erythematous scaly papules with crusting
Which areas are most commonly affected by atopic dermatitis?
1.INFANT– face and extensors
2. Children— back of the knees and the front of elbows ( flexures)
- Adults: hand and feet
What type of reaction is atopy?
Immediate onset allergic reaction
Type I hypersensitivity reaction
Rash on exposure to sun, after exercise, when getting angry or eating spicy food? What is the likely diagnosis?
Cholinergic Urticaria
Types of Urticaria
- Symptomatic dermographism
- Cold Urticaria
- Cholinergic urticaria
- Contact urticaria
- Delayed pressure urticaria
- Solar urticaria
- Heat Urticaria
- Vibratory urticaria
- Aquagenic urticaria
How do you diagnose cholinergic urticaria?
Pilocarpine Stimulation test
A pilocarpine stimulation test, also known as a sweat chloride test, is a procedure that uses pilocarpine to stimulate sweat glands and measure the amount of chloride in sweat. It’s the standard test for diagnosing cystic fibrosis (CF).
Classical appearance for cholinergic urticaria
A number of small (1–4 mm) punctate wheals, often surrounded by a larger erythematous flare
Wheals are itchy or burn
They may coalesce to form larger swellings.
What causes cholinergic urticaria?
Any stimulus that can cause excessive sweating can precipitate this inducible urticaria.
Footnote:
Exercise (most common trigger)
High temperature exposure, eg, hot water baths
Spicy food ingestion
Emotional stress.
Unique characteristic of cholinergic urticaria
Transient, starting within minutes of the trigger stimulus and resolving within 90 minutes after stopping the initiating activity.
It almost never occurs on the palms, soles, or axillae.
What is the treatment for cholinergic urticaria?
oral H1 second-generation antihistamines.
cetirizine, desloratadine, fexofenadine, levocetirizine, and loratadine
What is dyshidrotic eczema? or Pompholyx?
an itchy, chronic, recurrent, often symmetric eruption on the palms of hands, fingers, and soles of the feet
foot note:
also known as acute and recurrent vesicular hand dermatitis, acute palmoplantar eczema, vesicular endogenous eczema, or cheiropompholyx(hands); pedopompholyx ( foot)
clinical features of dyshidrotic eczema?
Small, deep-seated, fluid-filled blisters (vesicles) on the sides of the fingers, hands, and feet.
The vesicles are small (1–2mm), often symmetrical, with no associated erythema, and they do not occur elsewhere on the body. Vesicles may coalesce into larger blisters.
It is extremely itchy.
The vesicles commonly resolve after 2–3 weeks with scaling.
What is the treatment for dyshidrotic eczema?
- Potassium permanganate soaks
- Topical treatments:
Topical steroids (usually potent or ultrapotent)
Pimecrolimus and tacrolimus
Bexarotene gel
Regular use of emollients and moisturisers
Iontophoresis or botulinum toxin when used for hyperhidrosis
Topical antifungal medication if indicated for documented fungal infection.
Phototherapy:
Topical psoralens and ultraviolet light A (tPUVA).
Systemic treatments:
Antihistamines
A short course of oral corticosteroids for immediate relief
Oral antibiotics or antifungal agents if indicated for secondary skin infection
Most common metal responsible for contact dermatitis
Nickel
What are the types of contact dermatitis?
Irritant contact dermatitis
Allergic contact dermatitis
What type of hypersensitivity reaction is allergic contact dermatitis?
Type IV
Most common site for irritant contact dermatitis
Hands and forearms
Most common allergens causing allergic contact dermatitis
Pollen esp by Parthenium ( congress grass) and Metals
How is contact dermatitis diagnosed?
Patch Test
Foot note: reading is done after 48-72hrs ( 2 days) to see the signs of delayed hypersensitivity: 1st reading
2nd reading taken at 96 hrs( 4 days)
two types: open ( outer arm skin and uncovered) and closed ( applied to back and occluded)
What is urticaria pigmentosa?
Maculopapular cutaneous mastocytosis
Due to abnormal collections of mast cells in the skin causing brown patches and freckles.
It is the most common type of cutaneous mastocytosis.
What is Noonan syndrome?
