Granuloma Annulare

by | Nov 26, 2017

Background

Granuloma annulare is a delayed hypersensitivity reaction to some component of the dermis.

Inflammation is mediated by tumour necrosis factor alpha (TNFα). The reason that this occurs is unknown.

Causes of Granuloma Annulare

Disseminated Granuloma Annulare is more prevalent in diabetes, hyperlipidaemia, lymphoma, HIV infection, solid tumours

Localised granuloma annulare is sometimes associated with autoimmune thyroiditis but it does not clear up with thyroid replacement.

Features of Localised Granuloma Annulare

  • Annular plaque
  • Skin colour violet red
  • Margin feels beaded
  • Most common sites back of hands and feet
  • Frequently confused with tinea

Natural history of Localised Granuloma Annulare

Usually clears spontaneously within a few months or years

Treatment of localised granuloma annulare

  • Betamethasone Dipropionate 0.05% ointment BD 4-6 weeks
  • Mometasone Furoate 0.2% ointment bd 4-6 weeks
  • With or without occlusion

 

Erythema Nodosum

by | Nov 26, 2017

Erythema Nodosum is a probable high yield question on KFP as dermatology is something that lends itself to this format, with picture -> direct questions.

(more…)

Acanthosis Nigricans

by | Nov 26, 2017

Features of acanthosis nigricans

Hyperpigmented, hyperkeratotic areas

symmetrically distributed

Hyperkeratotitis

On axillae, groin, cub foss, pop foss

Multiple skin tags are associated

Causes of acanthosis nigricans

Insulin resistance

Diabetes

Internal malignancy – Maligancies of large and small bowel, ovaries, lung, breast, prostate, Stomach adenocarcinoma

Rare genetic disorders

Hypothyroidism

Polycystic ovaries

Oestrogens

Steroids

Nicotinic acid

Management of Acanthosis Nigricans

Weight loss an reverse changes in obesity

Refer non-obese patients

Erythema Multiforme

by | Nov 26, 2017

Causes of Erythema Multiforme?

Infections – Drug reactions

Infections

Herpes simplex virus (HSV) 1 and 2 infections (account for >50% of cases).

Mycoplasma pneumonia infections.

Fungal infections.

Other viruses (varicella-zoster virus, cytomegalovirus, hepatitis C virus, and HIV).

Drug reactions

Barbiturates.

Penicillins.

Phenothiazines.

Sulfonamides.

Anticonvulsants.

Non-steroidal anti-inflammatory drugs.

Vaccinations (diphtheria-tetanus, hepatitis B, smallpox).

Features of history and examination in Erythema Multiforme

few to hundreds of skin lesions erupt within a 24-hour period.

The lesions are first seen on the backs of hands and/or tops of feet, and then spread along the limbs towards the trunk.

The upper limbs are more commonly affected than the lower.

Palms and soles may be involved.

The face, neck and trunk are common sites.

Skin lesions are often grouped on elbows and knees.

There may be an associated mild itch or burning sensation

Differential diagnosis in Erythema Multiforme

Drug eruptions

SJS

TEN

Contact dermatitis

Urticaria

Urticarial vasculitis

Pityriasis rosea

Pemphigoid

Pemphigus

Investigations in Erythema Multiforme

Skin biopsy potentially

Managament of Erythema Multiforme

If a drug is thought to be responsible, it must be withdrawn.

If an infection is suspected, it should be treated.

Pharmacological Management of Erythema Multiforme

Apply emollient

Topical corticosteroid

Betamethasone Dipropionate 0.05% od 2 weeks

Betamethasone valerate 0.1% ointment once daily 2 weeks

Mometasone Furoate 0.1% daily 2 weeks