Scalp disorders: The scalp is unique among skin areas in humans, with high follicular density and a high rate of sebum production. Fingers, combs, hats, styling implements come into contact with the hair and scalp and can introduce microorganisms, increasing the likelihood of infections and infestations.
Dandruff and seborrheic dermatitis: Dandruff and seborrheic dermatitis are extremely common, affecting close to 50% of the world’s population (Cardin, 1998). They are overwhelmingly afflictions of adults, occurring most commonly between the ages of 15 and 50 years and very rarely before adolescence, although seborrheic dermatitis can continue to occur in extreme old age. Although dandruff and seborrheic dermatitis usually become apparent during the second and third decades following increased sebum production at the onset of puberty, the severity and duration of the symptoms vary widely.
Contact dermatitis: Contact dermatitis usually occurs on areas of your body that have been directly exposed to the reaction-causing substance — for example, along a calf that brushed against poison ivy or under a watchband. The rash usually develops within minutes to hours of exposure and can last two to four weeks.
Signs and symptoms of contact dermatitis include:
• A red rash
• Itching, which may be severe
• Dry, cracked, scaly skin
• Bumps and blisters, sometimes with oozing and crusting
• Swelling, burning or tenderness
Psoriasis: Psoriasis is a chronic, relapsing inflammatory disease that affects at least 2% of the population worldwide, with 50% of those cases involving the scalp. The lack of UV exposure and frequency of friction injury to the scalp may contribute to the scalp’s propensity to develop clinically evident psoriatic features. Psoriasis observed on the scalp could be an indication of psoriatic arthritis, as anywhere from 6 to 39% of those with psoriasis develop inflammation of the joints
Psoriasis of the scalp most commonly presents as well-circumscribed, red, scaly plaques, and papules covered by a silver-gray scale. Similar lesions may appear on other body parts, which can aid in diagnosis. Pruritus and burning may accompany the lesions and the severity can fluctuate with time. Hair shafts may appear funneled together, producing what is known as the “tepee sign”. Hair shafts may also be dry and brittle, and, in some cases, the disease process leads to telogen effluvium, causing extensive hair loss
Folliculitis: Folliculitis is an inflammatory condition affecting hair follicles. It appears as a small red tender bump occasionally surmounted with dot of pus surrounding a hair. Older lesions that have lost the pus appear as red bumps surrounding the opening of the follicle absent the hair. One to hundreds of follicles can be affected anywhere that hair is present. Actually, acne vulgaris, the facial rash that teenagers develop, is a type of folliculitis.
What are the causes of folliculitis?
Folliculitis can be caused by a large number of infectious organisms. However, frequently folliculitis is sterile and seems to be induced by irritating chemical substances, drugs, occlusive clothing, and physical irritants like shaving. Differentiating these causes is very important if the physician is going to be able to treat the condition successfully.
cicatricial or scarring alopecia: Primary cicatricial or scarring alopecia is a type of alopecia characterized by a destruction of hair follicles, and permanent hair loss. Why this happens isn’t entirely understood, but like alopecia areata, the cause is thought to involve the auto-immune system.
Distinguishing primary scarring alopecia from other types of alopecia, such as alopecia areata, can initially be difficult. This is because primary cicatricial alopecia causes the hair follicles to fill up with skin cells, areas of the skin on your scalp which experience this can be especially smooth and shiny. Further confusion can arise as there are often a few hairs interspersed throughout the affected area, and unlike alopecia areata, scarring alopecia often causes visible scalp inflammation and in certain cases, tufting of the hair, severe scaling and pustules. Treatment of small areas of cicatricial alopecia can be quite effective.
Head lice and nits: Head lice and nits are very common in young children. They don’t have anything to do with dirty hair and are usually picked up from head-to-head contact. Head lice grasp the hair shaft with hooklike claws. They don’t like light, and they’re fast, so you may see or feel the nits only when you closely examine your child’s hair.
Ringworm: Ringworm, also known as dermatophytosis or tinea, is a fungal infection of the skin. The name “ringworm” is a misnomer since the infection is caused by a fungus, not a worm.
Ringworm infection can affect both humans and animals. The infection initially presents with red patches on affected areas of the skin and later spreads to other parts of the body. The infection may affect the skin of the scalp, feet, groin, beard, or other areas.