Dermatology Flashcards
Common causes of nappy rashes
Irritant Dermatitis
Infantile seborrhoeic dermatitis
Candida infection
Atopic eczema
Rare Types
Acrodermatitis enteropathica - Associated with Zn deficiency and frequent diarrhoea
Melanocytic naevi
What is the most common type of napkin rash?
Irritant Dermatitis
Cause of Irritant dermatitis
It’s due to not changing nappies frequently or if the infant has diarrhoea.
Rash is due to the irritants in the urine.
Urea splitting organisms in faeces increase the alkalinity and likelihood of the rash.
C/F of irritant dermatitis
Affects convex surface of the buttocks, lower abdomen, top of thighs
The flexures are spared
Mx of Irritant Dermatitis
Frequent Changing of napkin
Keeping the baby without a napkin
Emollients
Topical steroids - 0.5% hydrocortisone
Does candida infections cause rashes or complicate existing rashes?
It can do both
C/F of candida infection
Erthyematous rash
Includes skin flexures
Satelite lesions
Mx of Candida infection
Anti-fungal drugs - Miconazole (Candid- B)
At what age does infantile seborrheic dermatitis present?
first 2 months of life
C/F of infantile seborrheic dermatitis
Starts in the scalp
Can spread to neck, behind ears, face, axilla, extend to flexures and napkin area.
Forms a cradle cap, a thick yellow adherent layer
Not itchy, Child not bothered by it
Mx of seborrheic dermatitis
emollients
Low concentrations Sulphur
Salicylic acid local application
Mild topical steroids - For widely spread rashes
Atopic eczema occurs around what age?
Usually first year of life but uncommon in the first 2 months.
What kind of family history is associated with atopic eczema?
Family Hx of atopic disorders such as eczema, asthma, allergic rhinitis.
What can delay the onset of eczema?
Exclusive breast feeding
Atopic Eczema Dx
Dx made clinically
Elevated plasma IgE level
If there is a Hx to suggest an allergic cause, Skin-prick and radioallergoabsorbent (RAST) tests can be done.
C/F of Atopic Eczema
Itching (Pruritus) - Main Sx, Results in exacerbation of the rash
The excoriated areas becomes erythematous and crusted.
Atopic skin is usually dry, and prolonged scratching and rubbing of the skin may lead to lichenification, in which there is an accentuation of normal skin markings.
What parts of the body are involved in infants and older children in atopic eczema?
Infants >2M old - Predominantly face, trunk, extensors
Older children - Predominantly flexors and friction surfaces
Causes of exacerbation of eczema
Bacterial Infections - Staph, strep
Viral infectons - Herpes simplex virus
Ingestion of an allergen - Egg
Environmental heat and humidity
Change or reduction in medication
Psychological stress
Idiopathic
Complications of atopic eczema
Eczematous skin can readily be infected, usually with Staph and Strep
Mx of atopic eczema
Avoiding Irritants and precipitants
Emollients - Mainstay of Mx, moisturizing and softening the skin. Should be applied liberally 2 or more times a day after a bath.
Topical Corticosteroids -
An effective Rx, must be used with care.
Mildly potent corticosteriods such as 1% hydrocortisone ointment can be applied to eczematous areas twice daily.
Moderately potent topical steroids is used in the mx of acute exacerbations, use must be kept to a minimum. Should be applied lightly and face avoided.
Antibiotics or antiviral agents -
Antibiotics with hydrocortisone. can be applied topically for mildly infected eczema. Systemic antibiotics for widespread infection.
Eczema herpaticum is rx with systemic aciclovir.
Itch suppression with an oral antihistamine - Chlorpheniramine
Psychosocial support if needed.
May have malnutrition, require nutritional advice
Melanocytic naevi risk and Mx
4-6% lifetime risk of subsequent malignant melanoma
Rx - Require prompt referral to paed dermatologist and plastic surgeon to assess feasibility of removal, oncologist might also be involved.
Most common cause of Bullous Impetigo
Staph. aureus
Also caused by Strep infections
C/F of Bullous Impetigo
Seen in the new born
Its uncommon
Potentially Serious blistering form of Impetigo
Bullae which breaks forming silvery crusted lesions
Course of infection in Bullous Impetigo
Superficial bullae form, which are fluid filled lesions, around mouth, genital area, abdomen. The bullae rupture and crust forming Silvery crusted lesions.
Mx of Bullous Impetigo
Cloxacillin, Flucloxacillin, Fusidic Acid, Soframycin Cream
Source/bacterium can come from the nose, nasal carriers can be destroyed by muperasine nasal application.
Child should not attend school until every single bullae has ruptured and crusted.
What’s the most superficial form of bacterial infection?
Bullous Impetigo
Autoinnoculation can spread lesions in Bullous Impetigo. T/F?
T
Types of Viral skin infections
Viral Warts
Molluscum contagiosum
Viral warts are caused by?
human papiloma virus (HPV)
Areas where viral warts occur
Fingers and soles (verrucae)
Mx of viral warts
Most disappear spontaneously over a few months or years
Rx is only indicated if the lesions are painful or are a cosmetic problem
Salicyclic acid, glutaraldehyde, cryotherapy
What causes molluscum contagiosum?
poxvirus
C/F of molluscum contagiosum?
Small lesions, skin coloured/white coloured, pearly papules with central umbilication/dimpling.
Single or usually multiple
Often widespread lesions
Rx of molluscum contagiosum?
Lesions tend to disappear spontaneously within a year
If necessary, a topical antibacterial can be applied to prevent or rx a secondary bacterial infection.
Cryotherapy (2-3s) can be done in older children to hasten the disappearance of chronic lesions.
Routes of spread of molluscum contagiosum
Contact
Common towels
Pathophysiology of Ringworm fungal infection
Dermatophyte fungi invade dead keratinous structures such as, horny layer of the skin, nails and hair.
Tineacapitis (Scalp ringworm), sometimes acquired from dogs and cats, causes scaling and patchy alopecia with broken hairs.
Why is the term RINGWORM used to describe the fungal infection?
Because of the often ringed (annular) appearance of skin lesions.
What’s a kerion?
A severe inflammatory ringworm patch
Dx of ringworm infection
Examination under filtered UV (Wood’s) light may show bright greenish/yellow fluorescence of the infected hairs with some fungal species.
Rapid dx can be made by microscopic examination of skin scrapings for fungal hyphae
Definitive identification of the fungus is by culture
Rx of Ringworm infection
Anti-fungals
If not severe, topical anti-fungals can be given - Miconozole
If severe, Systemic anti-fungals
Types of parasitic infections
Scabies
Pediculosis
Cause of Scabies - MO
Sarcoptes scabiei - 8 legged mite.
Burrows down the epidermis along the stratum corneum.
C/F of scabies
Severe itching occurs 2-6W after infestation and is worse in warm conditions and at night.
In older children - burrows, papules, vesicles involve the skin between the fingers and toes, axillae, flexor aspects of the wrists, belt line and around the nipples, penis and buttocks.
In infants and young children - Distribution includes palms, soles, trunk.
Head, neck and face can be involved in babies but is uncommon.
Dx of Scabies
Clinical dx - Presence of characteristic lesions on the soles and hx of itching.
Itching in other family members is a helpful indicator.
Confirmation can be made by microscopic examination of skin scrapings from the lesions to identify the mite, eggs and mite faeces.
Complications of scabies
Skin becomes excoriated due to scratching.
Secondary eczematous or urticarial reaction masking true dx.
Secondary bacterial infection is common, giving crusted, pustular lesions.
Acute glomerular nephritis can occur.
Slowly resolving nodular lesions are visible.
Mx of scabies
Whole family should be treated, affected or not.
For children, best Rx is permethrin cream. Apply below neck for 12-15hrs. (8-12hrs)
If face is involved, apply on face avoiding eyes.
For older children, Denzyl Benzoic cream.
General hygiene should be improved.
Pediculosis in Sinhala
Ukuno
Most common form of lice infestation in children
Pediculosis capitis (Head lice infestation)
Pediculosis is common in girls than boys. T/F?
T. Because of long hair
Pediculosis presentation
Itching of scalp and nape or identifying live lice on the scalp or nits (empty egg cases) on hairs.
There maybe secondary bacterial infection, often over the nape of the neck, leading to a misdiagnosis of impetigo.
Sub-occipital lymphadenopathy is common.
Where are louse eggs found, in pediculosis infestation?
Louse eggs are cemented to hair close to the scalp and the nits (Small whitish oval capsules) remain attached to the hair shafts as the hair grows.
Pediculosis Rx
Applying a solution of 0.5% malathion to the hair and leaving it on overnight.
Hair is then shampooed and the lice and nits are removed with a fine toothed comb.
Rx should be repeated a week later.
Permethrin can be used instead as well.
Psoriasis in sinhala
Pothu Kabara
T/F
1. Psoriasis is a familial disorder
2. Psoriasis presents before the age of 2
- T
- F (Rarely presents before the age of 2)
Types of psoriasis
Guttate type
Annular type
Guttate type of psoriasis presentation
Common in children
Often follows a Strep or viral sore throat or ear infection.
Small, rain drop like lesions, round or oval erythematous scaly patches on the trunk and upper limbs and attack usually resolves over 3-4M.
Most get a recurrence within the next 3-5yrs.
Chronic psoriasis presentation
Chronic psoriasis with plaques or annular lesions is less common.
Fine pitting of the nails may be seen in chronic disease but is unusual in children.
Occasionally, Children with chronic psoriasis develop psoriatic arthritis.
Rx of psoriasis
Guttate psoriasis is with ointments.
Coal tar preparations are useful for plaque psoriasis and scalp involvement.
Dithranol (inhibits keratocyte hyperpoliferation) preparations are very effective in resistant plaque psoriasis.
Pityriasis rosea causes
An acute, self-limiting condition
Thought to be of viral origin/ possible inflammation.
Pityriasis rosea C/F
Begins with a single round or oval scaly macule, the herald patch, 2-5cm in diameter, on the trunk, upper arm, neck or thigh.
After a few days, Smaller dull pink macules develop on the trunk, upper arms and thighs.
The rash tend to follow the line of the ribs posteriorly, described as the fir tree pattern/ Christmas tree pattern”.
Sometimes the lesions are itchy
Rx of Pityriasis rosea
No rx is required and the rash resolves within 4-6W
Steroids have a place
What are the causes of hair loss?
Immune mediated Eg: SLE
Fungal infections
Physical hair pulling
Genetics
What is alopecia totalis?
Total hair loss
Alopecia areata C/F
A common form of hair loss in children
Hairless, single or multiple non-inflamed smooth areas of the skin, usually over the scalp are present.
Remnants of broken off hairs, visible as ‘exclamation mark’ hairs may be seen at the edge of active patches of hair fall
The more extensive the hair loss, the poorer the prognosis, but regrowth often occurs within 6-12months in localised hair loss.
Alopecia areata Rx
There’s a place for steroids
Treat underlying disease
Psychiatry referral if due to trichotillomania
Dermatology referral
What is trichotillomania?
Pulling of hair
Formation of acne
Maybe begin 1-2 yrs before the onset of puberty following androgenic stimulation of the sebaceous glands and an increased sebum excretion rate.
An obstruction to the flow of sebum in the sebaceous follicle initiates the process of acne.
C/F of acne vulgaris
There are a variety of lesions, initially open comedones (black heads) or closed comedones (white heads) progressing to papules, pustules, nodules and cysts.
Lesions occur mainly on the face, back, chest and shoulders.
The more severe cystic and nodular lesions often produce scarring.
Menstruation and emotional stress may be associated with exacerbations.
Rx of acne vulgaris
The condition usually resolves in the late teens, although it may persist.
Topical rx is directed at encouraging the skin to peel using a keratolytic agent, such as benzoyl peroxide, applied once or twice daily after washing.
Sunshine, in moderation, topical antibiotics (erythromycin) or topical retinoids maybe be helpful.
For more severe acne, oral antibiotic therapy with tetracyclines (only when 12yrs old, because they may discolour the teeth in younger children) or erythromycin is indicated.
The oral retinoid, isotretinoin is reserved for severe acne in teenagers unresponsive to other rx.
T/F
1. Acne can be seen in New born
2. Doxycycline can be given during pregnancy
3. Erythromycin and doxycycline are antibiotics and immune-modulators
4. Tetracycline is given for children <12yrs
5. Isotretinoin is not given to pregnant women or girls of child bearing age.
- T
- F
- T
- F. Can cause teeth discoloration
- T
Types of skin rashes in systemic disease
Malar facial rash in SLE
Heliotrophic rash in dermatomyositis
Purpura over the buttocks, lower limbs, elbows in HSP
Erythema nodusum and erythema multiforme in OC usage, ulcerative colitis
C/F of stevens-johnson xd
A severe bullous form of erythema multiforme
involving the mucous membranes.
Eye -conjunctivitis, corneal ulceration and uveitis
ophthalmological assessment is required.
due to drug sensitivity or infection, with morbidity and sometimes even mortality from infection, toxaemia and renal damage.
Drugs that can cause Stevens-johnson Xd
Carbamezapine - Antiepileptic
Sulfanomide - Antibiotics
Causes of Erythema Nodosum
Strep infection
Primary TB
IBD
Drug reaction - Oral contraceptives
Idiopathic
Sarcoidosis - In adults
Causes of Erythema multiforme
Herpes simplex infection
Mycoplasma pneumoniae infection
other infections
Drug reactions
idiopathic
Strep infections
Presentation of Erythema multiforme and nodosum
Multiforme - Target lesions with a central papule surrounded by an erythematous ring Can be vesicular or bullous.
Nodosum - Tender nodules over the legs.
Cause of acute urticaria
Results from exposure to an allergen or a viral infection.
C/F of urticaria
Urticarial skin reaction
May also involve deeper tissues to produce swelling of the lips and soft tisues around the eyes (angioedema) and even anaphylaxis.
Characterised by Flesh-coloured weals.
C/F of papular urticaria
A delayed hypersensitivity reaction (IgE mediated) mostly commonly following a bite from a flea, bed bug, animal or bird mite, some drugs and food.
Most commonly seen in the legs.
Irritation, vesicles, papules and weals appear and secondary infections due to scratching is common.
May last for weeks or months and may be recurrent.
C/F of Hereditary angioedema
A rare AD disorder caused by the deficiency or dysfunction of C1-esterase inhibitor.
No urticaria, but subcutaneous swelling, often accompanied by abdominal pain.
The trigger is usually trauma.
Angioedema may cause respiratory obstruction. (Laryngeal edema)
Rx of hereditary angioedema
Purified preparation of the inhibitor, C1 Esterase, but replacement therapy with FFP can be used as a short-term measure.
Mx of Urticaria
Anti-histamine - chlopheniramine
Steroids
Pre-disposing factors of Hereditary angioedema
Stress
Menstruation
Chronic Urticaria
Persisting >6W
Usually non-allergic in origin
Results from a local increase in permeability of capillaries and venules.
