Chapter 1 — Introduction to Trichology

GP-Level Analogy

"Trichology is to hair what cardiology is to the heart — a discipline that takes a seemingly simple organ and reveals an extraordinarily complex system underneath. Just as the ECG made cardiac diagnosis systematic, trichoscopy makes hair diagnosis visual, reproducible, and teachable. You don't need to be a specialist. You need a framework."

Trichology is the medical and scientific study of hair and scalp disorders. In clinical practice, its defining value is the systematic ability to link what the patient tells you, what you see on examination, and what the dermatoscope reveals, into a diagnosis faster and more accurately than intuition alone allows.

The word derives from the Greek trichos (hair) + logos (study). Contemporary medical trichology is evidence-based, investigation-led, and increasingly therapeutically active, particularly following the advent of JAK inhibitors for alopecia areata and combination minoxidil-finasteride for androgenetic alopecia.

Why trichology belongs in general practice

Hair loss is among the top ten dermatological complaints presenting to GPs, yet fewer than 20% of GPs report confidence in its management. This is a gap trichology training can close.

50%

of men affected by AGA by age 50

40%

of women affected by FPHL by age 70

lifetime prevalence of alopecia areata

<20%

of GPs confident managing hair loss

90%

of common alopecias diagnosable without biopsy

Core definition for GPs

Trichology in GP practice = the systematic use of history + scalp examination + trichoscopy to diagnose hair and scalp disorders, exclude contributing systemic causes, initiate appropriate treatment, and identify when specialist referral is required.

A brief history of medical trichology

1860s–1902 — Formal recognition

The Institute of Trichologists founded in London (1902). Early focus on cosmetic hair and scalp treatments.

1950s–1980s — Medical foundations

Kligman (1961) described telogen effluvium. Ludwig (1977) classified female pattern hair loss. Hamilton and Norwood classified male AGA.

1990s–2000s — Dermoscopy revolution

Rudnicka et al. (2008) formally described trichoscopy, transforming non-invasive diagnosis.

2010s–2020s — Therapeutic revolution

JAK inhibitors for alopecia areata (Xing 2014; King 2022). Combination minoxidil-finasteride trials. S3 guidelines published. Trichology enters evidence-based medicine.

The scope of trichology in GP practice

Diagnosis

Differential diagnosis

Distinguishing AGA, TE, AA, scarring alopecias, tinea capitis, and trichotillomania using history, examination, and trichoscopy.

Investigation

Targeted investigation

Targeted blood panels (ferritin, TFTs, androgens) rather than blanket testing. Knowing when biopsy or referral is needed.

Treatment

Evidence-based treatment

Initiating topical/oral minoxidil, finasteride, and iron supplementation. Counselling on realistic expectations.

Red flags

Urgent pathology

Identifying scarring alopecias, virilisation, systemic disease, and malignant scalp disease.

Counselling

Patient communication

Explaining the hair cycle, treatment timelines, and prognosis. Managing the psychological burden of hair loss.

Monitoring

Follow-up assessment

Standardised photography, trichoscopy at follow-up, repeat blood panels. Knowing when to escalate or refer.

The psychological burden

Hair loss has clinically significant associations with depression, anxiety, reduced self-esteem, social withdrawal, and reduced quality of life — comparable in magnitude to other chronic diseases. The GP who dismisses hair loss without investigation is not being reassuring — they are being inaccurate.

Common GP errors in hair loss management

1. Diagnosing "stress hair loss" without investigation (missing iron deficiency, thyroid disease). 2. Reassuring a patient with scarring alopecia that it will "grow back." 3. Prescribing minoxidil for telogen effluvium without addressing the trigger. 4. Dismissing female hair loss as "normal ageing" without a ferritin check. 5. Failing to screen for autoimmune associations in alopecia areata.

The trichology diagnostic triad

The core clinical model of trichology is a three-step diagnostic triad: a structured history, a systematic scalp examination, and trichoscopy. These three elements, used together, allow confident diagnosis of over 90% of common hair and scalp conditions without biopsy.

Fig 1.1 — The trichology diagnostic triad

Fig 1.1: The trichology diagnostic triad. History generates hypothesis; examination refines; trichoscopy confirms. This sequential approach produces diagnoses faster and more accurately than any single element alone.

Step 1 — The structured history

A trichology history has nine specific domains (OPTICS-MFS) designed to distinguish the most common diagnostic categories within the first five minutes. The single most useful opening question: "Is your hair falling out or getting thinner?"

Step 2 — Systematic scalp examination (DICS)

DICS: Distribution (which zones? diffuse or patterned?), Inflammation (erythema, scale, crust?), Calibre (miniaturisation?), and Scarring (follicular ostia present or absent?).

Step 3 — Trichoscopy

At 10–20× magnification: dot patterns (yellow, black, white, red), shaft morphology (exclamation marks, comma hairs), perifollicular changes, and vascular patterns. Diagnostic accuracy exceeds 90% in experienced hands.

GP Analogy — The Triad

"History is taking witness statements. Examination is surveying the crime scene. Trichoscopy is forensic analysis. You need all three. Forensics without a crime scene, and a crime scene without witnesses, produces guesswork."

Classification of hair loss — the master map

Fig 1.2 — Master classification of alopecia

Fig 1.2: Master classification of alopecia. The first branch point — scarring vs non-scarring — determines reversibility, urgency, and referral pathway.

The scarring vs non-scarring distinction

Feature	Non-scarring	Scarring (cicatricial)
Follicular ostia	Present and visible	Absent — smooth atrophic skin
Reversibility	Potentially reversible	Irreversible — stem cells destroyed
Urgency	Investigate and treat	Urgent referral — every week matters
Examples	AGA, TE, AA, tinea capitis	LPP, FFA, DLE, folliculitis decalvans
Trichoscopy	Follicular openings with hairs; dot patterns	White dots (fibrosis); absent follicular units

The trichology clinical value framework

Fig 1.3 — From presentation to diagnosis: the trichology clinical pathway

Fig 1.3: The clinical pathway from presentation to diagnosis. History generates hypothesis; examination and trichoscopy confirm.

What this book equips you to do

After completing this book: take a structured 9-domain history in 5 minutes · perform DICS examination · interpret basic trichoscopy · diagnose and treat AGA, FPHL, TE, and patchy AA · identify scarring alopecias and refer urgently · order targeted investigations · counsel patients accurately on prognosis.

The GP's role: Diagnose, Initiate, Refer

GP manages independently

Common non-scarring alopecias

AGA / FPHL — minoxidil ± finasteride/spironolactone.

Acute TE — identify trigger, iron supplementation, reassure.

Patchy AA — autoimmune screen + intralesional triamcinolone.

Tinea capitis — systemic antifungal.

GP initiates, then refers

Refractory or complex cases

AGA/FPHL not responding after 12 months.

Chronic TE (>6 months) with no trigger.

Moderate-severe AA (ophiasis) — DPCP or JAK inhibitors.

Female HL with confirmed hyperandrogenism.

Urgent referral

Scarring and complex alopecias

Any scarring alopecia (LPP, FFA, DLE) — urgent referral.

Alopecia totalis/universalis — JAK inhibitors.

Virilisation + rapid hair loss — androgen-secreting tumour.

Kerion in childhood — urgent antifungal.

The trichology toolkit for the GP

Tool	Cost	Training	Value
Structured history (9 domains)	None	1 hour reading	Generates diagnosis in 80% of cases
DICS examination framework	None	Single teaching session	Confirms or refines hypothesis
Polarised dermatoscope (10×)	£50–£300	2–4 hour workshop	Confirms diagnosis; monitors treatment
Smartphone dermoscope attachment	£30–£80	Minimal	Adequate for GP-level trichoscopy
Standardised photography	None	Positioning protocol	Objective monitoring over time

Quick recall — mnemonics

Trichology triad: HET

H·E·T

History — 9 domains, OPTICS-MFS
Examination — DICS framework
Trichoscopy — confirms + quantifies
Link all three → diagnosis without biopsy (90%)

Classification: SNS

S·N·S

Scarring = follicle destroyed, irreversible
Non-scarring = follicle intact, reversible
Second question: patterned or diffuse?
First exam question: are ostia present?

Examination: DICS

D·I·C·S

Distribution — diffuse or patterned?
Inflammation — erythema, scale, crust?
Calibre — miniaturisation ratio?
Scarring — ostia present or absent?

GP role: DIR

D·I·R

Diagnose — AGA, TE, AA, tinea
Initiate — minoxidil, finasteride, iron, ILT
Refer — scarring, AT/AU, refractory
When in doubt: trichoscopy first, biopsy rarely

Chapter map

Chapter	Topic	Key GP skill
1	Introduction to trichology	Diagnostic framework, classification, scope
2	Hair and scalp anatomy	Follicle biology, hair cycle, PSU
3	Hair history and examination	9-domain history; DICS examination
4	Trichoscopy basics	Dot patterns YBWR, shaft morphology
5	Male pattern hair loss	Hamilton–Norwood; finasteride + minoxidil
6	Female pattern hair loss	Ludwig scale; multi-factorial; spironolactone
7	Telogen effluvium	3-month trigger rule; CHIPS; FTBVZ screen
8	Alopecia areata	YBET trichoscopy; JAK inhibitors; OCEAN prognosis

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References

1. Blumeyer, A., Tosti, A., Messenger, A., et al. (2011). Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men. Journal of the German Society of Dermatology, 9(Suppl 6), S1–S57. https://doi.org/10.1111/j.1610-0379.2011.07802.x
2. Gilhar, A., Etzioni, A., & Paus, R. (2012). Alopecia areata. New England Journal of Medicine, 366(16), 1515–1525. https://doi.org/10.1056/NEJMra1103442
3. Headington, J. T. (1993). Telogen effluvium: New concepts and review. Archives of Dermatology, 129(3), 356–363.
4. Hunt, N., & McHale, S. (2005). The psychological impact of alopecia. British Medical Journal, 331(7522), 951–953. https://doi.org/10.1136/bmj.331.7522.951
5. Jain, N., Doshi, B., & Khopkar, U. (2013). Trichoscopy in alopecias. Indian Journal of Dermatology, Venereology and Leprology, 79(5), 587–605.
6. Kanti, V., Messenger, A., Dobos, G., et al. (2018). Evidence-based (S3) guideline for androgenetic alopecia — short version. Journal of the European Academy of Dermatology and Venereology, 32(1), 11–22.
7. King, B., Ohyama, M., Kwon, O., et al. (2022). Two phase 3 trials of baricitinib for alopecia areata. New England Journal of Medicine, 386(18), 1687–1699.
8. Kligman, A. M. (1961). Pathologic dynamics of human hair loss: Telogen effluvium. Archives of Dermatology, 83(2), 175–198.
9. Ludwig, E. (1977). Classification of the types of androgenetic alopecia occurring in the female sex. British Journal of Dermatology, 97(3), 247–254.
10. Mubki, T., Rudnicka, L., Olszewska, M., & Shapiro, J. (2014). Evaluation and diagnosis of the hair loss patient: Part I. Journal of the American Academy of Dermatology, 71(3), 415.e1–415.e15.
11. Norwood, O. T. (1975). Male pattern baldness: Classification and incidence. Southern Medical Journal, 68(11), 1359–1365.
12. Price, V. H. (1999). Treatment of hair loss. New England Journal of Medicine, 341(13), 964–973.
13. Rudnicka, L., Olszewska, M., Rakowska, A., et al. (2008). Trichoscopy: A new method for diagnosing hair loss. Journal of Drugs in Dermatology, 7(7), 651–654.
14. Shapiro, J. (2007). Hair loss: Principles of diagnosis and management of alopecia. Martin Dunitz.
15. Sinclair, R. (1999). Diffuse hair loss. International Journal of Dermatology, 38(Suppl 1), 8–18.
16. Wolff, H., Fischer, T. W., & Blume-Peytavi, U. (2016). The diagnosis and treatment of hair and scalp diseases. Deutsches Ärzteblatt International, 113(21), 377–386.