Dermatology Flashcards
Name the 4 main functions of the skin
Protection, Thermoregulation, Sensation and Metabolism
Explain the changes of skin as it ages
The Epidermis becomes thinner and flatter,
making the skin appear paler and more translucent.
The number of melanocytes decrease, but the remaining melanocytes increase in size. There is uneven distribution of melanocytes leading to uneven pigmentation, i.e. Age Spots.
Skin becomes wrinkled, due to depletion of elastic fibres.
Skin becomes dry as a result of atrophy of sebaceous glands.
Name the three layers of the skin
Epidermis, Dermis and Hypodermis
How many sub-layers does the Epidermis have?
5
Name the sub-layers of the Epidermis (Superficial to deep)
Stratum Corneum, Stratum Lucidum, Stratum Granulosum, Stratum Spinosum/Basale (a.k.a. Germinal layer)
How many sub-layers does the Dermis have?
2
Name the sub-layers of the Dermis (Superficial to deep)
The papillary dermis and the reticular layer
What does the Hypodermis/Subcutaneous layer consist of?
Composed of adipose and connective tissue
What are the (4) functions of the Hypodermis/Subcutaneous layer?
Supports, nourishes, insulates, and cushions the skin.
Name the two distinct parts of hair
The follicle (embedded within root) and the hair shaft (visible part)
The name of the muscle that contracts to raise the hair in response to stimuli
Pilomotor muscles
Name the 3 components of the hair shaft
Cuticle, Cortex, Medulla
The properties of the Cuticle, Cortex and Medulla within the hair shaft
The cuticle is transparent and covers the
hair shaft, protecting and preventing it from losing moisture.
The cortex contains melanin which provides colour to the hair, stores oils, provides flexibility and elasticity, and adds shape.
The medulla is a inner hollow core that runs the length of the shaft.
Name the two types of sweat glands
Eccrine glands and Apocrine glands
Where on the body are Eccrine glands located?
Major sweat glands of the human body, found in virtually all skin, with the highest density in palm and soles, then on the head, but much less on the torso and the extremities.
Where on the body are Apocrine glands located?
Larger sweat glands, located in the axillary and genital regions.
What is the function of sweat glands?
Sweat glands function to produce sweat/perspiration, which collects on the surface, evaporates and cools the body
What is the function of nails?
Function to protect the tips of fingers and toes
What are the two most commonly used antibiotics used to treat bacterial skin infections?
Flucloxacillin, QDS. If allergic, to penicillin – Clarithromycin BD.
When treating a bacterial skin infection, what antibiotic does NICE recommend if the patient is pregnant?
Erythromycin if pregnant, but Clarithromycin also used.
When treating Cellulitis, if the infection is near eyes or nose, what antibiotic is recommended and why?
Co-amoxiclav because it has wider anaerobic coverage.
When treating mild, localised impetigo, what topical antiseptic is recommended?
Hydrogen peroxide 1%
If Hydrogen peroxide 1% is unsuitable for treating impetigo (e.g. close to eyes), what is recommended?
Topical antibiotic - Fusidic acid
If impetigo is widespread, what treatment options should be considered?
Topical antibiotics OR short course of Oral antibiotics.
When should antibiotics be given after an insect bite/stings?
Avoid antibiotics, But, consider IF any signs of infection.
In the event of a human or animal bite, in what circumstance should antibiotics be given?
If the bite has broken the skin and drawn blood.
In the event of a human or animal bite that has broken the skin and drawn blood, what antibiotic is first line?
Co-amoxiclav
The name of the most common anti-fungal used for skin infections?
Terbinafine (cream, gel or spray)
The name of the anti-viral used for the treatment of herpes simplex virus infections, chickenpox, and shingles. How often is the oral preparation taken?
Aciclovir (A-cy-clo-veer), 5 times a day!
The name of the insecticide cream/lotion used to treat scabies. What advise should you give to patients?
Permethrin (puh-mee-thrin).
Two treatments, once a week for 2 weeks.
Apply to whole body and then wash off after 8-12 hours.
Particular attention should be paid to the webs of the fingers and toes and lotion brushed under the ends of nails
The name of the insecticide cream/lotion used to treat crab lice. What advise should you give to patients?
Permethrin (puh-mee-thrin).
Two treatments, once a week for 2 weeks.
Apply to whole body and then wash off after 8-12 hours.
Paying particular attention to the eyebrows and other facial hair.
What is Erythema Multiforme what type of lesion does it characteristically present with?
A hypersensitivity reaction usually triggered by infections, most commonly herpes simplex virus and medications (NSAIDs and Penicillins).
It presents with a target lesion.
What is the name of the two immune-mediated dermatological emergencies that should always be considered and require early intervention?
Stevens-Johnson syndrome (SJS)
Toxic epidermal necrolysis (TEN)
When should you suspect Stevens-Johnson syndrome (SJS) or Toxic epidermal necrolysis (TEN)?
Severe target lesions and the skin begins to blister, mucous membrane involvement (mouth and eyes) and generally unwell
Name three medications that could potentially cause Stevens-Johnson syndrome (SJS) or Toxic epidermal necrolysis (TEN)?
Penicillin antibiotics, NSAIDs, Allopurinol.
Name the cells of the innate immune response
Neutrophils, Macrophages, Basophils, Eosinophils, Dendritic cells and Natural Killer cells.
Name the cells of the adaptive immune response
‘Lymphocytes’ - B cells, T cells and Natural Killer cells.
Which lymphocyte cell is considered to be part of both the innate and adaptive immune response? Why?
Natural Killer Cells.
They are able todestroy pathogens and infected cells without the need for prior activation by specific antigens.
In acute inflammation, which cell count would you expect to see raised on an FBC?
Neutrophils
What is a low neutrophil count called?
Neutropenia
When should you order an FBC?
When suspecting an infection
If there is concerns about blood loss/anaemia
To monitor white and red cell production
Which white blood cell is a marker of allergic reaction and/or parasitic infection?
Eosinophils
Name the four stages of wound healing
(1) Hemostasis
(2) Inflammation
(3) Proliferation
(4) Remodelling
What are the 4 steps involved when undertaking an dermatological examination?
(1) Inspection
(2) Describe (SCAM)
(3) Palpation
(3) Systemic Check
When should the ABCDE approach be used and what does it consist of?
Used if a lesion is pigmented and melanoma is suspected.
Asymmetry
Irregular Border
Two or more Colours within the lesion
Diameter > 6mm
Evolution and/or Elevation
If a skin lesion is localised, where is it on the body?
Restricted to only one area of the body.
If a skin lesion is on an extensor region, where on the body may it be?
Knees, elbows, shins
If a skin lesion is on an flexural region, where on the body may it be?
Body folds. E.g. groin, neck, popliteal, antecubital fossa, behind ears
What are the 3 morphological types of Basal Cell Carcinoma (BCC)?
Nodule
Superficial
Morephoeic
What is the most common morphological type of Basal Cell Carcinoma (BCC)
Nodule, 60-80% of cases
How would you describe a Squamous Cell Carcinoma (SCC) lesion?
Initially a small nodule, which enlarges, with a red/dark pink base.
Scaly/crusted centre, which may develop into an ulcer
Name the 4 main diagnostic tests for skin disorders
(1) Diascopy (glass test)
(2) Dermatoscopy
(3) Scrapings
(4) Biopsy
Name the 3 types of skin biopsy
Punch, Shave, Wedge
Name the condition: “Slighty raised bilateral erythematous subcutaneous nodules which are very tender to touch, commonly caused by IBD”
Erythema nodosum
Name the condition: “Patients with diabetes mellitus may have this, but it can also be associated with malignancy if rapid onset and widespread.”
Acanthosis Nigricans
Name the condition: “can be a marker of liver disease, especially if associated with alcohol or viral infection. More than 5 is clinically significant”
Telangiectasia/spider nevi
How long is the incubation period of a vairacella-zoster (chickenpox) infection?
14-21 days
In a vairacella-zoster (chickenpox) infection, how many days pre and post eruption is the individual infectious?
1-2 before eruption
5 days post eruption
How would you describe vairacella-zoster (chickenpox) lesions?
Begins as macular lesions and then develop into groups of vesicles on a erythematous base.
True or Fale: Impetigo is a viral skin infection?
False. Impetigo in a bacterial infection.
Which 2 bacteria commonly cause impetigo?
Staphylococcus Aureus
Streptococcus Pyogenes
Impetigo can be categorised into two main types. What are they called?
Bullous and Non-bullous
