Dermatology For Medical Finals (based On Newcastle University Learning Outcomes)

Hospital Based Practice – Blistering skin conditions. •

Skin failure. ○ Dehydration ○ Poikilothermia.  Loss of temperature control ○ Infection ○ Hypoalbuminaemia ○ High utput cardiac failure ○ Oedema

Erythroderma

•

Defined as erythema covering > 90%

•

Complication of. ○ Eczema ○ Psoriasis ○ Drug reactions Can cause. ○ Dehydration ○ Poikilothermia ○ Septicaemia ○ Hypoalbuminaemia ○ High output cardiac failure ○ Oedema Management. ○ Establish cause. ○ Rehydrate ○ Adquate nutrition ○ Temperature control ○ Monitor for septicaemia ○ Urgent dermotolgy referral.

•

•

Blistering • Causes.

○

•

•

Epidermolysis bullosa ○ Pemphigus ○ Pemphigoid ○ Toxic epidermal necrolysis ○ Acute dependent oedema Complications. ○ Dehydration ○ Poor nutrition ○ Septicaemia ○ Pain Management. ○ Hydration & nutrition ○ Monitor for infection ○ Analgesia ○ Burst blisters ○ Urgent dermatology referral

Eczema Herpeticum. • Diagnosis. ○ History of atopic eczema ○ Toxic ○ Pyrexial ○ Punctate erosions on face and upper trunk. •

Investigations. ○ Viral & Bacterial swabs. ○ FBC ○ CRP

•

Management. ○ IV Aciclovir ○ NEVER topical steroids Complications. ○ Encephalitis.

•

Facial Cellulitis. • Presentation. ○ Toxic ○ Pyrexial ○ Asymetrical facial swelling.  Red  Tender ○ Point of entry for infection. • Investigations. ○ Temperature ○ Swabs ○ Blood cultures ○ FBC ○ CRP • Differentials ○ Acute facial eczema ○ Rosacea ○ SLE • Management. ○ IV antibiotics. ○ Eg. benzylpenicillin •

Complications. ○ Cavernous sinus thrombosis

Cellulitis. • Presentation. ○ Toxic ○ Pyrexial ○ Swelling.  Unilateral  Painful  Hot ○ Point of entry for infection. • Investigations. ○ |Blood cultures ○ Swab ○ FBC ○ CRP • Differentials. ○ Varicose eczema ○ Gravitational syndrome ○ DVT ○ Psoriasis • Management. ○ IV antibiotics.  Benzylpenicillin  Flucloxacillin ○ Analgesia ○ Elevate leg

Acute Eczema. • Classify. ○ Atopic ○ Infected ○ Phototoxic ○ Allergic ○ Exfoliative. •

•

Investigations. ○ Swab ○ Patch test.  When settled Management ○ Emollient ○ Topical steroids ○ Antibiotics.

Acute Psoriasis • Diagnosis. ○ Guttate ○ Pustular ○ Erythrodermic • Triggers. ○ Strep. Pharyngitis ○ Drugs.

•

 Lithium  Beta – blockers  NSAIDs Management. ○ Emollient ○ Refer to dermatology.

Cutaneous vasculitis. • Diagnosis. ○ Painful ○ Palpable ○ Purpura. •

Investigations. ○ Causes.  Infection  Drugs  Endogenous  Autoimmune disease ○ Systemic involvement.  Urinalysis  eGFR  LFTs  CXR

Pyoderma gangrenosa. • Presentation. ○ Begins as pustules ○ Rapidly progress to ulcer. ○ Ulcer edge is  Inflammed  Bluish  Undermined • Associated conditions. ○ Inflammatory bowel disease ○ Rheumatoid disease ○ Monoclonal gammopathy •

Management. ○ Systemic steroids.

Skin ulcers. • Ulcers are abnormal breaks in an epithelial surface.

•

Leg ulcers affect 2% of the population in developed countries.

•

Causes. ○ Venous disease ○ Arterial disease.  Large vessel disease  Small vessel disease ○ Neuropathy ○ Diabetes.  Neuropathic  Vascular ○ Lymphoedema ○ Vasculitis

○ ○

○

○ ○ ○ ○

•

History. ○ ○ ○ ○ ○

○

•

Malignancy Infection.  TB  Syphilis Trauma  Pressure Pyoderma gangrenosum Drugs. May be multiple causes. For leg ulcers.  70% are venous  15% are mixed venous and arterial  2% are arterial. Length of history Number of ulcers. Pain History of trauma Co – morbidities.  Varicose veins  Peripheral artery disease  Diabetes  Vasculitis Is the patient particularly odd?  Consider self – inflicted ulcers.  Dermatitis artefacta

Examination. ○ Note features such as.  Site  Number  Surface area  Depth  Edge  Base  Discharge  Lymphadenopathy.  Sensation  Healing. ○ If ulcer is in the legs, look for evidence of venous insufficiency.  Check Ankle – Branchial pressure index. ○ Site.



Gravitational ulcers.

•

Tend to occur just superior to medial malleolus.

• •



Mostly related to superficial venous disease. May reflect venous hypertension ○ Via damage to deep vein valves  eg. Secondary to DVT. Venous hypertension.

•

Leads to development to superficial varicosities and skin changes. ○ Eg. Lipodermatosclerosis.  Skin

•

• ○

○

○

○

○

Cutaneous TB Tuberculosis colliquativa cutis. ○ AKA scrofuloderma. ○ Infected lymph node ulcerates to the skin.

Depth.  If not uncomfortable for patient, a probe can be used to measure depth.  Most commonly can be performed with neuropathic ulcers. Discharge.  Culture any discharge before staring antibiotics.  Antibiotics rarely work anyway.  Watery discharge is said to favour TB  Bleeding discharge normally indicates malignancy.

Edge.   

  ○

• Pigmentation • Inflammation Minimal trauma to leg leads to ulceration. ○ May take many months to heal

Temperature.  Ulcer and surrounding tissue is cold in ischemic ulcers  Warm and well perfused ulcers tend to have local causes. Surface area.  Draw map of the area to quantify and time any healing.  Wound > 4 weeks old is a chronic ulcer, compared with a acute ulcer. Shape.  Unusual morphology is often due to underlying mycobacterium infection.

• •

○

Induration

Base.

Eroded edge

• Suggest active and spreading disease. Shelved or sloping edge. • Suggests healing. Punched out edge. • Syphilis • Ischemic Rolled over/ everted edge. • Malignancy Undermined edge. • TB

Any muscle, bone or tendon destruction. • Malignancy • Pressure sores. • Ischemia  May be a grey – yellow slough. • Overlying pale pink base.  Slough. • Mixture of ○ Fibrin ○ Cell breakdown products ○ Serous exudates ○ Leucocytes ○ Bacteria ○ Doesn’t necessarily imply infection ○ Part of the normal healing process.  Granulation tissue. • Deep – pink gel – like matrix. • Contained within fibrous collagen network. • Part of normal wound healing process Associated lymphadenopathy.  Suggests. • Infection • Malignancy Position in extension/ healing.  Healing is heralded by. • Granulation • Scar formation • Epithelialization  Inflamed margins indicates extension. 

○

○

•

Investigations. ○ Skin and ulcer biopsy.  Vasculitis  Maligant changes  Ward’s test. • Doppler probe in centre of ulcer. ○ Look for underlying systemic disorders.

•

Management. ○ Often difficult and expensive. ○ Treat cause. ○ Focus on prevention.  Optimise nutrition  Reduce risk factors. • Drug addiction • Smoking  Expert nursing care • Community nursing team • Varicose leg ulcer clinic

•

4 – layer compression bandaging.

○ ○

Systemic antibiotics rarely is effective. Topical agents can help.  Silver sulphadiazine  Gentamicin.

Brown pigmented lesions. • Causes include. ○ Melanoma ○ Sun – related freckles. ○ Lentigos.  AKA moles.  Persistent brown macules  Often large than freckles. ○ Cafe – au – lait spots.  Faint brown macules.  If > 5, consider neurofibromatosis ○ Seborrhoeic keratoses/ warts.  Benign greasy – brown warty lesions.  Usually on the • Back • Chest • Face  Very commonly in the elderly. ○ Chloasma.  AKA melasma  Brown patches.  Especially on the face.  Related to pregnancy or pill use.  May respond to topical azelaic acid. ○ Systemic disease.  Addison’s disease.

•





Palmar creases

• Oral mucosa • Scars Haemochromotosis Porphyria cutanea tarda. • Brown lesions • Fragile skin • Blisters.