General Dermatology - Appearance

Pigmentation

Hypopigmentation

Hyperpigmentation

i) Large areas - common

• Pityriasis versicolor (in lighter skin)
• Post-inflammatory e.g. lichen planus

ii) Large areas - uncommon / rare

• Drugs e.g. chloroquine & amiodarone
• Urticaria pigmentosa (syn. mastocytosis)
• Ashy dermatosis (syn. erythema dyschormicum perstans)
• Haemochromatosis
• Addison’s disease

iii) Small areas - common

• Post-inflammatory e.g. gravitational eczema
• Melasma (syn. chloasma) - face
• Café au lait patch
• Drugs e .g. minocycline

iv) Small areas - uncomon / rare

• Morphoea
• Atrophoderma of Pasini & Perini
• Pigmented purpuric dermatoses (lower legs)
• Acanthosis nigricans (flexural)
• Pigmented flexural lichen planus
• Macular amyloidosis
• Dyskeratosis congenita ('dirty neck' syndrome)
• Xanthoma (yellow)

Shape

Annular

i) Common

• Tinea corporis - scale at margin
• Tinea faciei - scale at margin
• Pityriasis rosea – herald patch - fine collarette of scale
• Granuloma annulare - non-scaling
• Seborrheoic dermatitis of the trunk – can take on an annular / arciform appearance - scale

ii) Uncommon

• Sarcoid – non-scaling
• Erythema annulare centrifugum – scale at margin
• Erythema chronicum migrans (syn. Lyme disease) – non-scaling
• Subacute lupus erythematosus – can be annular or polycyclic, can scale
• Lichen planus - especially male genitalia
• Porokeratosis - sun exposed skin, lesions have a keratotic border
• Linear IgA disease , chronic bullous disease of childhood - can scale / crust
• Jessner’s lymphocytic infiltrate - can be arciform, non-scaling
• Morphoea - not truly annular but often has an annular violaceous border

Dermatomal

• Varicella zoster

Linear

• Koebner phenomena - the development of lesions in previously normal skin that has been subjected to trauma. This most commonly arises in psoriasis, lichen planus and vitiligo, but it can also be seen in cases of plane warts and molluscum contagiosum
• Striae
• Verrucous epidermal naevus
• Lichen striatus
• Incontinetia pigmenti

Other - variable / unusal

• Tinea incognito (steroid treated tinea)
• Dermatitis artefacta
• Domestic violence/ non-accidental injury
• Erythema ab igne
• Livedo reticularis
• Chronic superficial scaly dermatitis (syn. digitate dermatosis)
• Cutaneous T-cell lympoma / pre-lymphomatous eruptions
• Larva migrans

Dry / Scaly / Crusty / Rough

Dry skin

• Xerosis
• Asteatotic eczema

Scaly

• Psoriasis
• Bowen's
• Tinea
• Pityriasis rosea
• Pityriasis versicolor
• Seborrheoic dermaitis
• Discoid lupus erythematosus
• Erythema annulare centrifugum

Rough areas with follicular prominence

i) Common

• Keratosis pilaris

ii) Uncommon / rare

• Darier’s disease
• Pityriasis rubra pilaris gt;
• Lichen spinulosa
• Perforating keratotic disorders (mainly lower legs)

Crust / exudate

i) Common

• Impetigo
• Eczema (infected; discoid)
• Superficial spreading BCC
• Ulcers

ii) Uncommon

• Ecthyma

Palmoplantar keratoderma - marked hyperkeratosis of the palms and soles

• Eczema
• Psoriasis
• Climacteric
• Hereditary
• Pityriasis rubra pilaris
• Reiter’s syndrome
• Paraneoplastic

Patches & Plaques

Multiple

i) Common

• Psoriasis
• Discoid eczema
• Pityriasis rosea
• Pityriasis versicolor

ii) Uncommon / rare

• Acute febrile neutrophilic dermatosis (syn. Sweet’s syndrome)
• Sarcoid
• Chronic superficial scaly dermatitis (syn. digitate dermatosis)
• Cutaneous T-cell lymphoma / pre-lymphomatous eruptions
• Syphilis

Few

i) Common

• Tinea
• Granuloma annulare
• Necrobiosis lipoidica

ii) Uncommon / rare

• Discoid lupus erythematosus
• Morphoea
• Extra-genital lichen sclerosus
• Mycobacterium
• Jessner’s lymphocytic infiltrate
• Granuloma faciale
• Paget's disease of the nipple / extrammary Paget's disease (solitary lesions)
• Erythema chronicum migrans (syn. lyme disease)
• Erysipeloid

Macules & Papules

Common & face

• Acne vulgaris (comedones present)
• Rosacea (comedones absent)
• Peri-oral dermatitis
• Plane warts
• Xanthelasma
• Polymorphic light eruption
• Adenexal tumours (e.g. syringomata)

Common & other sites

• Molluscum contagiosum
• Papular urticaria (insect bites)
• Guttate psoriasis
• Papular dermatitis (a variant of eczema)
• Lichen planus (flat topped)

Uncommon

• Darier’s disease
• Sarcoid
• Pityriasis lichenoides
• Urticaria pigmentosa (syn. mastocytosis)
• Hand, foot and mouth disease
• Grover's disease

Rare

• Lymphomatoid papulosis
• Lichen nitidus
• Lichen spinulosa
• Lichen myxedematosus
• Lichen amyloidosis (mainly chinese / shins)
• Eruptive xanthoma
• Langerhans cell histiocytosis
• Gianotti-Crosti syndrome (secondary viral infection in children)

Nodules

Common

• Acne vulgaris
• Scabies

Uncommon

• Nodular prurigo
• Gout
• Sarcoid
• Rheumatoid
• Multiple lipomatosis

Rare

• Mycobaterium
• Nodular amyloid
• Juvenile xanthogranuloma (yellow-brown)
• Lymphocytoma cutis
• Lymphoma and leukaemia cutis
• Leishmaniasis
• Skin metastases
• Xanthoma
• Zoonoses can cause papules, pustules, nodules and necrosis and most commonly occur on exposed areas of the body

Vesicles & Bullae

Vesicles

i) Generalised

• Varicella zoster
• Herpes zoster in immunodeficiency
• Eczema herpeticum
• Dermatitis herpetiformis
• Pityriasis lichenoides acuta
• Lymphomatoid papulosis (necrotic)

ii) Localised

• Herpes zoster
• Herpes simplex
• Pompholyx
• Hand, foot and mouth disease

Bullae

i) Generalised - common

• Bullous impetigo
• Drug eruptions

ii) Generalised - uncommon /rare

• Pemphigoid
• Pemphigus
• Linear IgA disease
• Erythema multiforme
• Toxic epidermal necrolysis
• Epidermolysis bullosa

iii) Localised - common

• Oedema
• Burns
• Impetigo
• Papular urticaria (insect bite)

iv) Localised - uncommon

• Pemphigoid
• Photodermatoses (drug induced; plant; porphyria; lupus erythematosus)
• Fixed drug eruption
• Benign familial pemphigus (syn. Hailey-Hailey disease - flexures)
• Epidermolysis bullosa

Pustules & Carbuncles/Furuncles (boils)

Pustules

i) Common

• Acne vulgaris
• Folliculitis
• Inflammatory cases of tinea

ii) Uncommon

• Pustular psoriasis (palmoplantar or generalised)
• Acropustulosis
• Acute febrile neutrophilic dermatosis (syn. Sweet’s syndrome)
• Subcorneal pustular dermatosis

Carbuncles / furuncles

• Infection
• Hidradenitis suppurativa
• Pyoderma gangrenosum

Ulceration & Necrosis

Wide distribution (i.e. can involve any site)

i) Common

• Herpes zoster

ii) Uncommon / rare

• Drug eruptions
• Pityriasis lichenoides acuta
• Lymphomatoid papulosis
• Cutaneous T-Cell lympoma
• Ecthyma gangrenosum
• Leishmaniasis (exposed areas)

Legs

i) Common

• Leg ulcers (venous / arterial / mixed)

ii) Rare

• Pyoderma gangrenosum
• Vasculitis
• Cryoglobulinaemia

Mucosal / Genetalia

• Apthous ulcers
• Erosive lichen planus
• Bechet’s disease
• Syphilis

Vascular

Vascular lesions

• See skin lesion table (vascular naevi)
• Leg ulcers – as above
• Vasculitis

Telangiectasia

i) Common

• Spider telangiectases
• Benign telangiectases
• Costal fringe
• Radiation dermatitis

ii) Uncommon

• Hereditary haemorrhagic telangiectasia
• Telangiectasia macularis eruptiva perstans
• Generalised telangiectasia - essential

Structural changes

These include firm areas of skin, weak areas of skin, and increased skin elasticity

Firm patches of skin

• Lipodermatosclerosus (lower legs, common - venous insufficiency)
• Morphoea
• Systemic sclerosis
• Sclerodema
• Mucinosis including pretibial and follicular
• Cutaneous calciphylaxis (associated with renal failure and dialysis)

Weak patches of skin

• Extra-genital lichen sclerosus
• Atrophoderma of Pasini and Perini
• Anetoderma

Skin laxity - general

i) Common

• Solar elastosis

ii) Rare

• Ehlers-Danlos syndrome
• Cutis laxa
• Pseudoxanthoma elasticum
• Lipoatrophy

Racially pigmented skin

Rashes specific to racially pigmented skin

• Dermatosis papulosa nigra
• Acne keloidalis nuchae
• Facial afro-caribbean childhood eruption ‘FACE’
• Voight's lines