Hair And Scalp Disorders: 6 Major Conditions And Treatments

Hair loss, excessive hair growth, and various scalp conditions represent a significant portion of dermatological consultations. These disorders can be broadly categorised into hair shedding, alopecia (diffuse or localised), hair shaft abnormalities, skin diseases affecting the scalp, and excessive hair growth such as hirsutism or hypertrichosis. Understanding the hair growth cycle—anagen (growth), catagen (transition), and telogen (resting)—is fundamental, as disruptions in these phases underlie many conditions.

Introduction

Hair serves protective, sensory, and thermoregulatory functions, with the scalp hosting approximately 100,000 follicles. Normal daily shedding ranges from 50-100 hairs, but excessive loss or growth signals pathology. Balding may be

scarring

(permanent follicle destruction) or

non-scarring

(reversible). Scalp evaluation involves assessing oiliness, lesions, inflammation, and hair pull tests. Diffuse thinning often stems from pattern balding, while localised patches suggest alopecia areata or infections. This article covers diagnosis, causes, and management comprehensively.

Hair Shedding

**Hair shedding** is a normal physiological process but becomes pathological when excessive, leading to visible scalp exposure. Acute events like surgery, illness, or medications trigger

telogen effluvium

, where up to 90% of anagen hairs enter telogen prematurely, causing diffuse shedding 2-3 months post-event.

Anagen effluvium

, seen in chemotherapy, results in brittle, fractured hairs due to mitotic arrest in growing follicles.

Chronic telogen effluvium mimics female pattern hair loss but is distinguished by pull tests yielding telogen hairs. Management focuses on addressing triggers: iron supplementation for deficiency, thyroid correction, or stress reduction. In severe cases, shedding progresses to baldness if untreated.

Diffuse Alopecia

**Diffuse alopecia** involves widespread thinning without distinct patches. In men,

androgenetic alopecia

(male pattern baldness) features frontal recession and vertex thinning due to dihydrotestosterone sensitivity. Women experience

female pattern hair loss (FPHL)

with central parting widening, sparing the frontal hairline.

Other causes include systemic lupus erythematosus, syphilis, iron deficiency (thin fragile hair), or hypothyroidism (coarse dry hair). Adolescents rarely present with pattern balding; suspect nutritional or endocrine issues. Diagnosis employs trichoscopy showing miniaturized hairs and scalp biopsy if needed. Treatments: minoxidil topically, finasteride orally (men), spironolactone (women), or low-level laser therapy.

Localised Alopecia

**Localised alopecia** manifests as patches of baldness.

Alopecia areata

, an autoimmune disorder, causes round, smooth patches with exclamation mark hairs (short, tapered broken stubs). It affects 2% lifetime risk, associating with atopy, thyroid disease, vitiligo, or Down syndrome. Variants: alopecia totalis (scalp), universalis (body-wide), or ophiasis (occipital band).

Inflammatory patches with erythema, scaling, or pustules in children suggest

tinea capitis

(fungal, with kerion),

folliculitis

, or

psoriasis

.

Scarring alopecia

(cicatricial) shows shiny pale skin, absent follicles: lichen planopilaris, discoid lupus, or folliculitis decalvans. Traction alopecia from tight hairstyles affects frontal margins, reversible if early. Trichotillomania presents asymmetrical broken hairs from plucking, managed with CBT.

Condition	Features	Scarring?
Alopecia areata	Smooth round patches, exclamation hairs	No
Tinea capitis	Scaling, pustules, hair breakage	Possible
Lichen planopilaris	Perifollicular erythema, scarring	Yes
Traction alopecia	Frontal fringe loss	No (early)

Hair Shaft Abnormalities

**Hair shaft disorders** are rare genetic conditions diagnosed via light/electron microscopy or dermoscopy, presenting in infancy with short, unruly, or fragile hair. Common types:

• Trichorrhexis nodosa: Node-like swellings leading to breakage from trauma or argininosuccinic aciduria.
• Monilethrix: Beaded, elliptical shafts with periodic fragility.
• Pili torti: Twisted, flattened shafts in Menkes disease or ectodermal dysplasia.
• Uncombable hair syndrome: Spun-glass appearance due to longitudinal grooving.

Management is supportive: gentle care, avoid trauma. Biotin or cysteine supplements may help select cases.

Skin Diseases Affecting the Scalp

Scalp skin diseases often cause itch, scaling, or inflammation, sometimes with secondary alopecia. Evaluate for oiliness, plaques, or pustules.

Condition	Clinical Features
Dandruff (pityriasis capitis)	Diffuse fine scaling
Seborrhoeic dermatitis	Yellowish greasy plaques, flexures
Psoriasis	Well-defined erythematous plaques, silvery scale
Pityriasis amiantacea	Sticky asbestos-like scale (psoriasis/seborrhoea)
Head lice	Nits, excoriations
Lichen simplex	Lichenified itchy plaques (occiput)
Folliculitis	Pustules around follicles

Treatment: antifungals/shampoos for dandruff/seborrhoea (ketoconazole), coal tar for psoriasis, pediculicides for lice.

Excessive Hair Growth

**Hirsutism** is androgen-dependent male-pattern hair in women (face, chest, abdomen). Causes: PCOS (80%), idiopathic, or tumours.

Hypertrichosis

is non-androgenetic excess lanugo/terminal hair, congenital or acquired (drugs, malnutrition).

Investigate hormones (testosterone, DHEAS). Treatments:

• Physical: Shaving, waxing, electrolysis, IPL, laser.
• Medical: Spironolactone, cyproterone acetate, eflornithine cream.

Hirsutism may coexist with scalp thinning mimicking male pattern.

Frequently Asked Questions (FAQs)

Q: What causes sudden hair shedding?

A: Telogen effluvium from stress, illness, or medications; resolves by addressing trigger.

Q: Is alopecia areata permanent?

A: Often regrows spontaneously; totalis/universalis less favourable, treat with corticosteroids.

Q: How to differentiate FPHL from telogen effluvium?

A: Biopsy or trichoscopy; FPHL shows miniaturization, chronic effluvium excessive shedding.

Q: Can scalp conditions cause permanent baldness?

A: Yes, scarring alopecias like lichen planopilaris destroy follicles.

Q: What are safe treatments for hirsutism?

A: Anti-androgens after excluding pregnancy; cosmetic removal for hypertrichosis.

Q: When to see a dermatologist for hair loss?

A: Patchy loss, rapid shedding, associated scalp symptoms, or no improvement with OTC.

Wigs are subsidised for medically necessary cases. Seek evidence-based advice; avoid unproven remedies.