Rash

Infectious

Autoimmune

Drugs

Malignancy (melanoma, hypopigmented mycosis fungoides)

Nutrition

Pellagra (vit B3 (niacin))

viral

Bacterial

Dengue/ Zika/ Chikugunya

RSMF

Fungal

HSV/ HIV / VZV

Lyme

tinea versicolour

tinea corporis/capitis

measles

Coxsackie A

salmonella typhi

Staph aureus

strep throat

SLE

dermatomyositis

Derm

dry skin (age/menopausal)

  • congenital vs acquired
  • distribution (localized/generalised, Sun exposure)
  • colour
  • non melanocyte ddx / systemic syndromes

Parasitic

Scabies

Candida (+satellite lesions)

Metabolic

Uremia

Thyroid

Liver disease

Trauma to skin (post-inflammatory hypopigmentation/hyperpigmentation)

Deposition

Agyria (silver)

Stasis dermatitis (CVI)

DM dermopathy

Macular amyloidosis

Capillaritis (haemosiderin)

Ecthyma (deep impetigo)

Lichen sclerosis

Vasculitis (painful, burning, post-inflammatory hyperpigmentation)

Primary skin lesion

Derm conditions (eczema/folliculitis/heat rash (papular)

  • TRO melanoma or mycosis fungoides
  • reactive perforating collagenosis (familial OR acquired)

Secondary skin lesion

Prurigo nodularis

Lichen simplex chronicus