Lecture 6 - Acne, Eczema, Psoriosis, Rosacea Flashcards
What is the function of the stratum corneum and how is it affected?
The stratum corneum acts as a barrier to ingress and egress. It also control water loss. The health of the stratum corneum is affected by too much water loss.
What if NMF and what is it used for?
Natural moisturising factor is an endogenous breakdown product of filaggrin hydrolysis. It is a hygroscopic misture of amino acids, PCA, urea and lactic acid. NMF plays a vital role in maintaining water in the stratum corneum
The role of NMF is to maintain flexibility, integrity, cohesion and hydration of the stratum corneum. It also act as a buffer, so if NMF decreases pH increases.
How does filaggrin matter?
Individual normally have 10,11 and 12 filaggrin repeat units, fewer unit cause drier skin.
If there is a loss of filaggrin, it causes deformation of corneocyte (flattening of skin surface cells). Less filaggrin will lead to less amount of NMF and then there will be a rise in the pH of the skin. Higher pH increases activity of serine proteases which will digest the lipid-processing enzyme and desmosomes. They also produces active cytokines which will cause inflammation of the skin.
Describe atopic eczema.
It is the most common form of eczema which occurs in mostly babies from 3 months and it resolves in childhood but can sometimes continue in adulhood. It presents itself as dry scaly itchy rash on face, scalp, neck, inside elbows and behind knees.
Describe irritant contact eczema.
This results from damage to skin from topically applied liquid or chemicals in absence of allergic mechanism.
Describe allergic contact eczema.
This happens through a allergic mechanism whereby a patient comes into contact of an allergen, an eczematous rash is formed.
Give the available treatment for eczema.
Can use emollients or emulsifying ointments to avoid dryness and cracking of skin.
Use topical corticosteroids to help with the inflammation and itchiness.
Sedating antihistamines will help with the itchiness.
Avoid soap, wool fabrics and synthetic materials.
Describe Seborrhoeic eczema.
It is a common harmless scaling rash affecting scalp, face, eyebrows, ear, folds of underarms and groin. Dandruff is a case of seborrhoeic eczema of the scalp and cradle cap in infant may be the same condition.
It is related to the proliferation of the normal skin yeast. It is not related to diet but can be related to stress, illness, and change of season.
Give the treatment and advices for seborrhoeic eczema.
Seborrhoeic eczema in adult is very persistant. Generally it can be kept under control by regular use of antifungal agent and intermittent use of topical steroids.
In infants, it normally clears before 6 months but if it persists up to a year, emollient cream, hydrocortisone cream and topical ketoconazole can be used.
On the scalp, one can use medicated shampoos such as ketoconazole, selenium disulphide, zinc pyrithione, coal tar and salicylic acid, 2 times a week for a month. Steroid will help to reduce the symptoms and it should be applied daily for a few days so often.
On the ears, chest and back, the affected area should be cleansed once or twice per day. Ketoconazole must be used once daily for 2- 4 weeks. Hydrocortisone cream can be used up to 2 times daily for 1-2 weeks
What is systemic lupus erythematosus?
It occurs in women between the age 35 and 45. It presents as a butterfly rash on cheeks and nose. Other symptoms are non specific joint pain, fatigue and rapid hair loss. It is normally triggered by sunlight or other stresses which increase the skin circulation. Systemic lupus erythematosus can be life threatening.
What is psoriasis?
It is a chronic scaling disease with associated skin inflammation or redness. It appears as raised, rough reddened areas covered with fine silvery scales. It is common on the back of the elbows and on the knees.
This happens because of an abnormality in epidermal cel differentiation which occurs at a 10 times faster rate than normal.
What are the causes of psoriasis?
Infection - throat or upper respiratory tract infection.
Trauma - surgical incisions, burns, rubbing, scratching, sunburn or local infection of the skin.
Emotional stress or anxiety
Climatic factors - sunlight
Cetain drugs - Beta blocker, lithium, chloroquine, NSAIDs, ACE inhibitor and alcohol abuse.
State the different types of psoriasis.
- Plaque psoriasis - raised scaly patched on knees, elbows and scalp. Lesions can be itchy and sore.
- Guttate psoriasis - teardrop shaped patches scattered all over the body, may sometimes follow by throat infection.
- Flexural psoriasis- affect skin to skin contact area. it tends to occur later in life.
- Generalised pustular psoriasis - acute, severe eruption of superficial pustules with reddening skin and high fever. Due to use of large quantities of steroids cream or tablet to treat psoriasis.
- Pustular psoriasis- chronic localised on hands and feet. happens in middle age.
- Psoriatic arthritis - inflammatory joint disease affecting joint of hands and feet.
How can psoriasis be managed?
It cannot be treated so the symptoms are managed.
Can use emollients for hydrating the skin, use steroids for the symptoms.
Use vitamin D3 as it interferes with the cell differentiation
Other options are coal tar, salicylic acid, dithranol and retinoids.
Where topical treatment has failed, patient are given phototherapy such as UVB light or PUVA therapy.
PUVA combine UVA radiation with psoralen as it enhances the effect of UVA.
Systemic treatment available for psoriasis are methotrexate 10-25 mg weekly, acitrecin or cyclosporin
What is acne vulgaris?
It is a skin condition which is characterised by the formation of blackheads/whiteheads, nodules, papules or cysts. It can be inflammatory and non inflammatory. It commonly appears on the face, shoulders.
