Conditions

Why every page starts with a layer

Skin is built in layers, and almost everything about a condition follows from which layer it involves. Something confined to the outermost sheet of dead cells behaves differently from something in the living epidermis below it, and both behave differently again from something involving the blood vessels of the dermis.

Depth explains why one condition scales and another flushes, why some itch and others do not, and why a clinician presses on an area before saying anything about it. It also explains what will heal without a mark and what will not, since damage above the junction between epidermis and dermis renews completely and damage below it does not.

What each page contains

The pages follow one shape, so that the second is easier to read than the first. Each opens with a direct answer, then the cross-section, then what is actually happening in the skin, then the words a dermatologist would use, then what a consultation usually involves and what is worth asking in it.

Every page carries an explicit note about seeing a dermatologist, a short section stating what the page does not do, a handful of common questions, and its sources with the date each was checked. None of that is decoration. A page about a skin condition that cannot say where its claims came from is asking for trust it has not earned.

The pages that carry nothing commercial

Four of these pages are marked as serious in the site's own configuration, and the marking has consequences enforced at build time rather than by good intentions. Melanoma, moles, psoriasis and vitiligo carry no affiliate content of any kind, no product categories and no commercial blocks anywhere on them.

Those pages are also written differently. They describe what clinicians look for and link to the published criteria at source rather than paraphrasing them, because a checklist reworded is a checklist changed, and on this particular subject that is not a risk worth taking for the convenience of not clicking through.

What you will not find

No page here matches a description to your skin, ranks conditions by likelihood, or offers a route from a symptom to a name. That absence is the whole design. Self-assessment against a written description is unreliable in both directions, and it sends as many people away from an appointment as towards one.

All conditions

• Acne: what it is, and how a dermatologist looks at it

  What acne is at the level of the follicle, the words dermatologists use to describe it, what a consultation usually involves, and what is worth asking.

• Actinic keratoses: the record of a lifetime of sun

  What actinic keratoses are, why they appear where sunlight has fallen for decades, the words a clinician uses about them, and why they are monitored. No diagnosis, no treatment advice.

• Cold sores: a virus that never quite leaves

  What a cold sore is, why the virus stays for life once acquired, the words a clinician uses about it, and what triggers a recurrence. No diagnosis, no treatment advice.

• Contact dermatitis: when the skin reacts to something it has touched

  The difference between irritant and allergic contact dermatitis, why the pattern on the skin matters so much, what patch testing is for, and what to ask.

• Eczema and atopic dermatitis: what the skin barrier has to do with it

  What atopic eczema involves at the outermost layer of the skin, why the barrier matters, what a consultation covers, and the questions worth asking about it.

• Fungal nail infection: why it takes so long to resolve

  What a fungal nail infection is, why the nail plate makes it slow, the words a clinician uses about it, and why a sample is usually taken. No diagnosis, no treatment advice.

• Fungal skin infections: what lives in the outermost layer

  Why fungal skin infections stay in the dead outer layer, what ringworm actually is, why the ring shape appears, and what a dermatologist checks at a consultation.

• Hidradenitis suppurativa: a follicular condition, not an infection

  What hidradenitis suppurativa is, why it favours skin folds, the words a clinician uses about it, and why it is so often mistaken for recurrent boils. No diagnosis, no treatment advice.

• Hives and urticaria: the rash that moves

  What a weal is, why hives appear and disappear within hours, the difference between acute and chronic urticaria, and what a dermatologist will want to know.

• Impetigo: a surface infection with a golden crust

  What impetigo is, why it stays at the surface of the skin, the words a clinician uses about it, and what a consultation covers. No diagnosis, no treatment advice.

• Keratosis pilaris: rough bumps that are not spots

  What keratosis pilaris is, why the bumps sit at hair follicles, the words a clinician uses about it, and why it is treated as harmless. No diagnosis, no treatment advice.

• Lichen planus: an immune attack at the junction

  What lichen planus is, why it affects the mouth and nails as well as the skin, the words a clinician uses about it, and what a consultation covers. No diagnosis, no treatment advice.

• Melanoma and skin cancer: what clinicians look for

  How skin cancers arise, the difference between melanoma and the non-melanoma types, how a suspicious lesion is assessed, and where the published guidance sits.

• Melasma and hyperpigmentation: when the skin makes more pigment

  What melasma is, how it differs from marks left by inflammation, why depth of pigment matters so much, and what a dermatologist assesses at a consultation.

• Moles, and when to get one checked

  What a mole is at the level of the skin, why change over time is what clinicians care about, how a mole is examined, and what the published guidance covers.

• Molluscum contagiosum: small domes that wait it out

  What molluscum contagiosum is, why the spots have a dimple in the centre, the words a clinician uses, and why waiting is so often the plan. No diagnosis, no treatment advice.

• Pityriasis rosea: the rash that announces itself first

  What pityriasis rosea is, why one patch appears before the rest, the words a clinician uses about it, and why it is left to resolve. No diagnosis, no treatment advice.

• Psoriasis: an immune condition that shows on the skin

  What psoriasis involves in the epidermis, why it is understood as an immune condition rather than a skin complaint, what a consultation covers, and what to ask.

• Rosacea: what it is, and how a dermatologist looks at it

  What rosacea involves in the dermis, why it is often mistaken for acne or sensitive skin, what a consultation covers, and the questions worth asking.

• Scabies: a mite, a burrow and a delayed reaction

  What scabies is, why the itch arrives weeks after the mites do, the words a clinician uses about it, and why household contacts come up. No diagnosis, no treatment advice.

• Seborrhoeic dermatitis: the rash that follows the oil glands

  Why seborrhoeic dermatitis appears where sebaceous glands are densest, what yeast has to do with it, how it differs from dandruff, and what to ask at a consultation.

• Shingles: what it is, and why it follows a line

  What shingles is, why the rash keeps to one side of the body, the words a clinician uses about it, and what a consultation covers. No diagnosis, no treatment advice.

• Vitiligo: when pigment cells stop working in patches

  What happens to melanocytes in vitiligo, why it is understood as an autoimmune condition, what a consultation involves, and the questions worth asking.

• Warts and verrucas: the same thing in two places

  What a wart is, why a verruca looks different despite being the same infection, the words a clinician uses, and what a consultation covers. No diagnosis, no treatment advice.