Pathologies of the Scalp: Clinic, diagnosis and treatment

• Scalp diseases include a wide range of other pathologies.
• Many factors can therefore come into play depending on the pathology: immunological, toxic, medicinal, traumatic, infectious, hormonal, localization of a general disease of the scalp or a specific scalp condition.

Circumscribed Non-Scarring Alopecia

Alopecia Areata

• It affects approximately 1 to 2% of the general population. However, the prevalence can vary between 0.1 and 6.9% depending on the population studied².
• It mainly affects children (25%) and young adults, but all age groups can be affected^1-3.
• Alopecia Areata is multifactorial, and the precise causes of its occurrence are still debated.
• However, genetic and immunological factors (autoimmunity) always seem to be involved^1,2.
• Other factors such as oxidative stress, epigenetics or the intestinal microbiota could also play a role³.

Trichotillomania and Trichotemnomania^1,4

• Trichotillomania is a form of obsessive-compulsive disorder. This condition mainly affects women (75%).

• Trichotemnomania refers to the cutting and/or shaving of hair in a manipulative and/or compulsive act. It often indicates an underlying psychological problem.

Alopecia by Trauma and Traction^1,5

• Ephemeral alopecia related to prolonged abusive hair pulling.
• It is often considered as affecting mainly people of African origin, however recent studies suggest that the main risk factor is not the type of hair but the maintenance habits.

Infectious and Inflammatory Alopecia¹

• • Any inflammation of the scalp can cause local hair loss (seborrheic dermatitis, shingles, insect bites).
  • If it remains superficial, it is reversible.
  • If it becomes chronic or deep, it can turn into scarring alopecia.   

Alopecia in Clearings¹

• Characterized by temporary alopecia.
• Occurs in 5% of cases following secondary syphilis.

Androgenetic Alopecia^1,6

• • Androgenetic alopecia (=baldness) affects 30% of Caucasian men in their 30s, 50% in their 50s and 80% in their 70s. It is also estimated that 30% of women are affected.
  • Men of Asian or African origin seem to be less affected by this phenomenon.
  • It is linked to two main factors: androgenic stimulation and genetics.
  • One of the genes involved is carried by the X chromosome.
  • This genetic background is associated with hair follicles (especially those on the top of the head) that are more sensitive to dihydrotestosterone, leading to an alteration in the hair renewal cycle: the cycle is accelerated and shortened, with early exhaustion of the number of cycles.
  • Androgenetic alopecia also concerns women, in whom it can be triggered by oral contraceptives (pill) or hormonal treatments prescribed during menopause. Alopecia in women is also influenced by stress and excess cholesterol.

Diffuse Non-Scarring Alopecia

Telogen Effluvium^1,7,8

• This is one of the most common causes of alopecia.
• Multiple factors can be at the origin of it: cerebral trauma, diet, childbirth, breast feeding, or medication.

Anagenic Effluvium (Dystrophic)¹

• This is a sign of acute alteration of the anagen follicle which leads to dystrophy of the hair matrix, triggering hair loss by fracture of the hair shaft.
• It is distinguished from the telogen effluvium by a trichogram examination.

"Non-Alopectic" Alopecia¹

• Some patients suffer from hair loss that cannot be linked to effluvium or alopecia.
• This is the case for dysmorphophobia or seasonal hair loss.

Scarring alopecia

This type of alopecia includes several pathologies, in particular specific scalp  and hair follicle conditions (primary scarring alopecia), dermatoses with a particular localization (secondary scarring alopecia)¹.

Inflammatory Scarring Alopecia

• Chronic lupus erythematosus.
• Lichen planus: in women over 30.
• Follicular degeneration syndrome: it never affects children and only rarely affects men.

Pustular Scarring Alopecia¹

• Infectious Pustulosis:
  • May develop following folliculitis.
  • The search for infectious causes is very important.

• Quinquaud Folliculitis Decalvans:
  • It is a chronic folliculitis.
  • It affects both men and women.
• Dissecting Cellulitis of the Scalp (DCS) (Perifolliculitis Capitis Abscedens, Suffodiens or Hoffman disease):
• May be associated with acne conglobata and hidrosadenitis suppurativa forming the acne triad.
• More often found in men.
• Tufted Folliculitis: affecting mainly people with black skin.
• Sterile Pustulosis: affecting the elderly.

Non-Inflammatory Scarring Alopecia¹

• Pseudopelade of Brocq: it mainly concerns women aged 25 to 45 years old.
• Fibrosing Frontal Alopecia: it is usually found in post-menopausal women but can affect men and women of all ages.
• Alopecia Musinosa.

Circumscribed Non-Scarring Alopecia¹

Alopecia Areata^1-3

• Manifested by spontaneous hair loss in a specific area (20% of cases) or in multiple areas.
• The areas are circumscribed, often circular. The size can vary, and the progression can be centrifugal (patchy alopecia).

• If the occipital region is affected, it is called ophiasic alopecia areata. This form is very resistant to treatment.

• In 5% of cases, the entire scalp can become bare, which is called alopecia totalis.

• If the hair loss is diffuse (rare), it often progresses very quickly.

• In 10% of cases, nails may also be affected.
• The evolution of the disease is unpredictable, however, nearly 2/3 of patients recover spontaneously or respond to treatment.
• If the progression is rapid, if more than 25% of the scalp is affected, if the nails are affected or if the disease is ophiasic, then the prognosis is unfavorable.

Androgenetic Alopecia^1,6

• It is associated with diffuse hair loss.
• In men, it is associated with a symmetrical regression of the temporal edges until two bare gulfs are obtained. There is then a recession of the frontal border and a toning down of the top of the skull, which can be moderate or advanced. By progression and convergence, we obtain a Hippocratic baldness where only the temporal-occipital crown remains.
• In women, it is characterized by preservation of the temporal and frontal borders and occipital regions. There is an oval thinning of hair on the vertex and parietal region, rarely balding.
• The Ludwig scale details the stages of androgenetic alopecia.

Diffuse Non-Scarring Alopecia

Telogen Effluvium^1,7,8

• It is very frequent.
• Various factors can interrupt the growth phase of hair (anagen phase) and cause it to enter a resting phase, which then results in delayed hair loss 3 to 4 months later, which can affect up to 50% of the hair mass.
• Spontaneous repair with return to a normal cycle takes 6 to 12 months.

Anagenic Effluvium (Dystrophic)¹

• It is triggered by cytostatic drugs, the main ones being cyclophosphamide, docetaxel, paclitaxel.
• They cause a hair growth inhibition in the anagen phase resulting in a loss of all hair within 2 weeks following the first dose of treatment.

Scarring Alopecia

The pathological processes lead to the destruction of hair follicles, thus resulting in permanent alopecia. Treatments are generally not very effective¹.

Inflammatory Scarring Alopecia

• Chronic Lupus Erythematosus (SLE):
  • One or more large, erythematous, alopecic plaque covered with adherent scales, infiltrated at the edges and atrophic in the center.
  • Sometimes painful or pruritic.

• Lichen Planus: in 50% of cases, other lichen localizations are found on the body, which confirms the diagnosis.

• Follicular Degeneration Syndrome:
  • It starts in the center of the vertex and spreads slowly in a centrifugal manner.
  • It may be inflammatory, accompanied by pustules or increased local sensitivity.

Pustular Scarring Alopecia¹

• Quinquaud Folliculitis Decalvans:
  • Presence of small, round, hairless patches dotted with pinhead follicular pustules.
  • By progressive extension, linked to the confluence of the plaques, a vast atrophic area bordered by the active pustular lesions can be observed.

• Dissecting Cellulitis of the Scalp (DCS) (Perifolliculitis Capitis Abscedens, Suffodiens or Hoffman disease):
  • Presence of large erythematous nodules evolving towards suppuration.
  • The evolution is chronic.

• Tufted Folliculitis: it is characterized by the presence of tufts of hair emerging from a single orifice, resembling synthetic hair implants.

Non-Inflammatory Scarring Alopecia¹

• Pseudopelade of Brocq: multiple, rounded or oval patches of smooth surface, small in size and then progressively spreading with the "appearance of footsteps in the snow".

• Fibrosing Frontal Alopecia (FFA): appearance of a smooth, symmetrical band of alopecia affecting the frontal region and the pre-auricular regions with progressive recession of the anterior hairline.

• Alopecia Mucinosa:
  • The lesions are localized or diffuse.
  • They are characterized by follicular keratotic papules.
  • These papules are isolated or grouped in rather well-limited, erythematous plaques.

Diffuse Non-Scarring Alopecia¹

• Target the etiology to eliminate the triggering drug or toxicant.
• Treatment of deficiencies: iron, zinc, vitamins, etc.

Androgenetic Alopecia⁹

• Male: finasteride 1mg/day taken orally and/or minoxidil 2 or 5% applied topically. Complementary hair transplant.
• Female: minoxidil 2% and 5% applied topically after menopause.

Alopecia^1-3

• The first line of treatment is topical fluorinated corticosteroids. A monthly triamcinolone acetonide intradermal injection may also be considered, as it is more effective.
• These two treatments may be accompanied by 5% of minoxidil.
• The use of calcineurin inhibitors is not effective.
• If corticosteroids fail, immunotherapy can be prescribed by application of haptens to the scalp.      

Scarring Alopecia

It requires specific targeted treatments administered in hospital.

Tips For Your Patients

Androgenetic Alopecia

• Fight against seborrhea of the scalp, an aggravating factor in alopecia.
• Do not hesitate to wash your hair every day with a mild, non-detergent, sulfate-free shampoo to avoid reactionary hyperseborrhea.
• Avoid drying hair at high temperatures, which promotes seborrhea.

Dandruff

• Use an anti-dandruff shampoo, 3 times a week during the attack period, then once or twice a week for maintenance, alternating with a mild non-detergent shampoo.
• Factors that irritate the scalp and aggravate dandruff should be avoided: blow-drying, brushing hair vigorously, hair coloring with ammonia, unsuitable detergent shampoos.