Lecture 7 - the rest Flashcards
What is scabies?
Scabies is an infestation of the skin by the mite Sarcoptes scabiei. This parasite lives into burrowed tunnel in the stratum corneum. The burrows are normally a few mm to a cm long. The typical areas where infestation will manifest are the underarms, buttocks, elbows, knees, wrist and waistline. It causes pruritic lesions which is worse at night.
What is the available treatment for scabies?
First line treatment is permethrin which should be applied to the whole body and wash after 8-14h and it is repeated after 7 days.
Second line is Lindane but is it not recommended in children under 2 years as it can cause seizures because is its neurotoxicity.
Precipitated sulphur 6-10% in petrolatum is applied for 24h for 3 consecutive days.
Ivermectin is used in resistant cases and in norwegian scabies.
What is lice?
Pediculosis most commonly known as lice is an infestation of a parasite of a wingless, bloodsucking insect. They can infest the scalp, body, pubis and eyelashes. They are normally transmitted due to close contact.
Who is more prone to head lice and how is it diagnosed?
It is most common in girl of age 5 to 11 but it can still affect everyone. An active infestation usually involves less than 20 lice and it can be diagnosed with the wet hair combing technique. It is very pruritic.
What are the symptoms and causing factor of body lice?
Body lice primarily live in bedding and clothing. They cause intense pruritis and one will see small bites on their body especially on buttocks, shoulders and abdomen. It is normally contracted due to crowded conditions and low socioeconomic status.. Diagnosis by seeing live lice in seams of clothing.
What are the treatments for lice?
It depends if it is head, body or pubic lice. There are a number of products available for head lice. Dimeticone (4%) can be applied to dry hair and scalp, it is allowed to dry and wash after 8h. This is repeated after 7 days. Malathion (0.5%) can be applied to dry hair and scalp, left to dry naturally then washed after 12h. This is repeated after 7 days as well. Malathion is less effective than Dimeticone due to resistance.
While using these products, it is advised to do the wet hair combing every 4 days for 2 weeks for any hatched eggs.
Permethrin is active but is not recommended for head lice.
There is no topical treatment for body lice as the lice live in the clothing and bedding. But pruritis and secondary infection should be treated.
For pubic lice, one can use malathion 0.5% or permethrin 5%, which should be apply to the whole body, left to dry and washed off after 12 h. It should be repeated after 7 days.
For the eyelashes, it is recommended to apply petrolatum ointment 3-4 time a day for 8-10 days. Can also use fluorescein drops 10-20% can be applied to the eyelids. Fluorescein is a pediculocidal agent.
What are boils(skin abscesses)?
These are tender nodules caused by the infection of staphylococcus, often in the hair follicles. Furuncles are often visible on the neck, face, breast and buttocks. It can be very painful if on nose or ears. Carbuncles are just a cluster of furuncles connected subcutaneously which often causes scarring.
The predisposing factors are hot and humid conditions, bacterial colonisation of the skin and abnormal follicular anatomy. It can affect healthy young people but it is more common in obese, immunocompromised, elderly or diabetic patients.
It is diagnosed by culture from the furuncle or carbuncle.
What are the treatment for boils?
If it is a single lesion, it should be allowed to drain with occasional hot compresses. Furuncles on the face is normally treated with topical antibiotics.
In cases of large lesions or immunocompromised patients, systemic antibiotics is considered. Incision or drainage is occasionally necessary
If it occurs very frequently, it can be prevented using liquid soap containing chlorhexidine gluconate or by maintenance of systemic antibiotics.
What is impetigo?
It is a superficial infection caused by staphylococci or streptococci.
The risk factors of impetigo are moist environment, poor hygiene and nasal carrier of staphylococci. It normally presents itself as clusters pf pustules which break and form honey coloured crust.
Ecthyma is an ulcerative form of impetigo. It presents itself as small, prurulent, shallow, punched out ulcers with brown-black crusts.
Ecthyma and impetigo can be painful and pruritis is very common. Scratching can spread infection.
What are the treatment for impetigo?
Fusidic acid 2% can be applied 3-4 times daily.
If MRSA, muriprocin 2% can be applied tds for 10 days.
If it is extensive, one should be referred and they will be given flucloxacillin and clarithromycin.
What is photosensitivity?
It is a reaction of the skin to sunlight. Its symptoms are redness, urticaria and rash in mild cases. In extreme cases, it may cause dizziness, wheeziness and other systemic complications. Photosensitivity can occur after exposure to some drugs.
It is treated depending on the cause, for example if it is caused by chemical or cosmetics, one will use corticosteroids and avoid the causing agent.
There are two type of drug induced photosensitivity, phototoxicity and photoallergy. Give their definitions.
Phototoxicity occurs when light absorbing chemicals directly generate free radicals and inflammatory mediators. The symptoms are pain, erythema and damage. This reaction does not require prior sun exposure. The causes of phototoxicity can be due to topical or ingested agents.
Photoallergy occurs when there is a type IV immune response, light causes and structural change in the drug which then bind to tissue/protein which function as a hapten. Typical causes are aftershave lotions, sunscreens and sulfonamides. The symptoms are erythema, pruritus and sometimes vesicles.
Provide the classes and examples of drug induced photosensitivity.
Acne drugs - Isotretitoin
Antibiotics - sulphonamides, quinolones, trimethoprim, tetracyclines
Antidepressants - tricyclics
Antifungals - griseofulvin
Antuhyperglycemics -sulphonylureas
Antimalarial - Chloroquine, quinine
Antipsychotics - phenothiazines
Anxiolytics- alprazolam
Chemotherapy drugs - methotrexate, 5-FU, vinblastine
Diuretics - furosemide, thiazides
Cardiovascular drugs - amiodarone, quinidine
Topical preparations - antibacterials (chlorhexidine), antifungals, coal tar, fragrances, sunscreens
What are the risk factors for severe complications in burns?
If burn is over 40% of the BSA, age is over 60 or under 2. Presence of trauma or inhalation of smoke.
Name the different classes of burn with a definition.
First degree burn is burn limited to the epidermis which is tender and painful.
Second degree burn is divided into superficial and deep.
Superficial is limited to the upper half of the dermis which heals within 2-3 weeks. It is very painful and tender. vesicles form within 24 hours
Deep second degree burn involves bottom half of the dermis. It is less painful and tender than superficial burn. It takes for than 3 weeks to heal. Burns tend to be very dry as well.
Third degree burn involve burn up to the underlying fat.
