Module 8: Nails, Hair, Warts, and Corns Quiz

Module 8: Nails, Hair, Warts, and Corns

• This module covers various conditions related to nails, hair, warts, and corns.

Hair Disorders

• Androgenic alopecia: Hair loss in men and women, often influenced by hormones.
• Telogen effluvium: A condition where large amounts of hair are shed from the scalp.
• Alopecia areata: Autoimmune condition causing hair loss in patches.

Some Basic Science about Hair Follicles

• Hair follicle: The embryonic structure producing hair shafts.
• Hair shaft: The visible part of the hair.
• Hair types: Mature follicles can produce vellus or terminal hairs.
• Number of follicles: Approximately 5 million on the human body, and 100,000 on the scalp.
• Daily hair shedding: 100-200 hairs are shed daily from the scalp.
• Active growth phase: 85-90% of hairs are actively growing at any given time.
• Hormonal influence: Hormones affect hair follicle structure and function, impacting how much hair is produced depends on location.
• Immunologically privileged site: Hair follicles are locations where foreign grafts can survive for a time without immune rejection.
• Immune system targets: The immune system can target hair follicles due to primary attacks by immune mediators or a breakdown of immune privilege.
• Stages of the hair follicle cycle: The modules lists anagen (growth), catagen (regression), and telogen (resting) phases.
• Duration of phases: The anagen phase typically lasts 2–6 years, while catagen lasts 2-3 weeks in the scalp hair follicle. Telogens lasts up to three months.
• Location-dependent effects: The effects of hormones on hair follicles are dependent on where they are located on the body.

How Many Hair Follicles on the Scalp (Approximately)

• Approximately 100,000

How Many Terminal Scalp Hairs Shed Each Day

• 300-500 hairs

What Percentage of Human Scalp Hair Actively Growing

• 80-90%

Areas of Skin Without Hair

• Glabrous skin (e.g., palms, soles, mucous membranes).

Why Do Beards Grow Where They Do? Why Does Acne Occur in Certain Places More Than Others?

• The causes are related to hormonal influences and location-specific follicle sensitivity, possibly based on different follicle density/types, not elaborated on in the text.

Why Does Patterned Baldness Follow a Pattern?

• Male and female patterned baldness follows a predictable pattern dictated, in part, by hormonal influences on various parts of the scalp (specific locations of follicles or follicle density).

Nails

• Nail abnormalities: Ridging, splitting, thickening, onycholysis (nail lifting), psoriasis, acute and chronic paronychia (inflammation around the nails), fungal nail infections, nail nevi (moles) and melanomas.
• Onychodystrophy: Nail abnormalities like ridging, splitting, and thickening.
• Nail pitting/Median tic deformity: A nail condition with irregularities.
• Nail psoriasis: Nail condition linked to psoriasis.
• Onychomycosis (fungal nail infection): Nail condition caused by fungal infection.
• Paronychia (acute): Inflammation around the nail, often bacterial (secondary to trauma).
• Paronychia (chronic): Chronic inflammation around the nail (potential yeast or fungal infection).
• Nail Nevi/Melanoma-: Pigmented nail conditions/cancers.

Warts

• Human papillomavirus: Causes various types of warts.
• Common wart types: Vulgaris, palmoplantar, flat, genital (condyloma acuminata).
• Treatment options: Cryotherapy, topical immunomodulators, chemical destruction.
• Other information: Extensive warts may require immunosuppression consideration.
• HPV/Warts: Potential relationship between human papilloma virus (HPV) and warts.
• Molluscum contagiosum: Viral infection causing skin bumps with central umbilication, characterized by pox virus, in particular, and also linked to spread through the use of shared objects.

Alopecia Areata

• Localized autoimmune hair loss (scalp).
• Potential association with other autoimmune disorders.
• Often improves spontaneously.
• Totalis/Universalis forms affect the whole scalp or body, respectively.
• Treatment options include topical steroids, other topical immunosuppressives or systemic medications.

Alopecia—Hair Loss: Disruption in Normal Hair Cycle

• Describes subtypes of hair loss, categorized as loss or decreased development.
• Other types of alopecia are outlined, such as Areata, Androgenetic, Trichotillomania (hair pulling), Inflammatory/Scarring, Genetic alopecia. Shedding subtypes like Telogen effluvium are noted as well as anagen effluvium.

Anagen vs Telogen Effluvium

• Anagen effluvium: Hair loss affecting actively growing hair. Usually due to chemotherapy or other impacts on the follicle mitotic activity.
• Telogen effluvium: Hair loss affecting resting hair follicles. Common after stressful life events or illnesses. Shedding is often diffuse.

Corns/Calluses

• These are thickened areas of skin caused by pressure points (arising from repetitive activities or specific skin structures).
• Treatment focuses on off-loading pressure and using topical agents (salicylic acid/urea).

Additional Information

• Several other conditions and associated images were discussed—often with a clinical presentation. These conditions or circumstances include a case of a patient with leukemia facing hair loss (anaphase, catagen, telogen), a 30-year-old with HIV having bothersome skin warts, and a teenager with an autoimmune patch of hair loss related possibly to a broader autoimmune disorder.