Dermatology Notes for Competitive Exam part 2

Dermatology Notes Part 2

Vector Borne Skin Disease

Vector-borne skin diseases are infectious skin diseases that are transmitted to humans through the bite of a vector, such as mosquitoes, ticks, fleas, or sandflies. These diseases can cause various skin manifestations, including rashes, itching, and sores.

Rocky Mountain Spotted Fever (RMSF) 

Rocky Mountain spotted fever (RMSF) is a serious and potentially life-threatening bacterial infection caused by Rickettsia rickettsii. This disease is transmitted to humans through the bite of infected ticks, primarily the American dog tick, Rocky Mountain wood tick, and brown dog tick.

Clinical feature

Symptoms of RMSF usually appear within 2-14 days after being bitten by an infected tick. Initial symptoms may include fever, headache, muscle aches, and a characteristic spotted rash that typically starts on the wrists and ankles and spreads to the trunk of the body. Other symptoms may include nausea, vomiting, abdominal pain, and loss of appetite.

RMSF can be a serious and potentially fatal illness if not treated promptly. In severe cases, it can cause complications such as respiratory failure, kidney failure, and neurological problems. People who are at higher risk for developing severe RMSF include those who are over 40 years old, have a weakened immune system, or have delayed treatment.

Treatment

Treatment for RMSF involves the use of antibiotics such as doxycycline, which is usually given for a period of 5-10 days. Early treatment is critical to prevent severe complications, and prompt diagnosis and treatment can lead to a full recovery. In some cases, hospitalization may be necessary, particularly for patients who have severe symptoms or who are at higher risk for complications.

Prevention

Prevention of RMSF involves taking steps to avoid tick bites, such as wearing long-sleeved clothing, using insect repellent, and checking for ticks after spending time in wooded or grassy areas. If you develop any symptoms after being bitten by a tick, it is important to seek medical attention promptly.

Also read Dermatology Notes Part 1

Lyme Disease

Lyme disease is a tick-borne bacterial infection caused by the bacterium Borrelia burgdorferi. It is most commonly transmitted to humans through the bite of infected black-legged ticks, also known as deer ticks.

Clinical feature

Symptoms of Lyme disease usually appear within 3-30 days after being bitten by an infected tick. The most common early symptom is a characteristic rash called erythema migrans, which appears as a bull's eye rash with a central clearing. Other early symptoms may include fever, headache, muscle aches, and fatigue.

If left untreated, Lyme disease can progress to later stages and cause more serious symptoms such as joint pain and swelling, neurological problems, and heart palpitations. In some cases, people with Lyme disease may develop chronic symptoms that can persist for months or even years after the infection is treated.

Treatment

Treatment for Lyme disease involves the use of antibiotics such as doxycycline, amoxicillin, or cefuroxime axetil, which are usually given for a period of 2-4 weeks. Early treatment is important to prevent the development of more serious symptoms and complications.

Prevention

Prevention of Lyme disease involves taking steps to avoid tick bites, such as wearing long-sleeved clothing, using insect repellent, and checking for ticks after spending time in wooded or grassy areas. If you find a tick attached to your skin, it is important to remove it promptly using tweezers and to clean the bite area with soap and water.

Also read anatomy and physiology of skin

Fungal Skin Diseases

Fungal skin diseases are conditions caused by fungal infections that affect the skin, nails, or hair. Fungi are organisms that can thrive in warm, moist environments, and can infect the skin through direct contact with an infected person or contaminated object.

Tinea corporis: 

This is a fungal skin infection commonly known as ringworm. It causes a circular or ring-shaped rash that is itchy, red, and scaly. It can affect any part of the body, including the scalp, groin, and feet. 

Tinea capitis: 

This is a fungal infection of the scalp and hair shafts, which can cause hair loss and scaling of the scalp. It is most common in children. 

Onychomycosis: 

This is a fungal infection of the nails, which can cause thickening, discoloration, and deformity of the nails. It is commonly caused by the same fungi that cause athlete's foot. 

Candida: 

This is a fungal infection caused by an overgrowth of the Candida fungus. It can affect the skin, nails, and mucous membranes, and can cause a variety of symptoms, including itching, redness, and discharge. 

Oral thrush:

This is a type of Candida infection that affects the mouth and throat. It causes white or yellow patches on the tongue, mouth, or throat, and can cause pain or difficulty swallowing. 

Tinea versicolor: 

This is a fungal infection of the skin that causes patches of discolored, scaly skin that can be lighter or darker than the surrounding skin. It is caused by an overgrowth of the yeast Malassezia, which is normally found on the skin. 

Treatment of Fungal Diseases

1. Tenia Corporis

• Topical Antifungal (imidazoles). 
• Systemic Antifungal (griseofulyin, azoles, terbinafins) if unresponsive to topical treatment. 

2. Tenia Capitis

• Oral antifungal. 

3. Onchomycosis

• Oral antifungal (very difficult to treat). 

4. Candida

• Reduce moisture and friction in affected areas (weight loss and body powders). 
• Topical antifungal (nystatin) or oral antifungal. 

5. Tenia Versicolor

• Topical antifungal
• Selenium sulphide shampoo
• Oral antifungal (rarely needed) 

Acne Vulgaris

Acne vulgaris, commonly known as acne, is a chronic skin condition that occurs when hair follicles become clogged with oil and dead skin cells. It can affect people of all ages but is most common during adolescence.

The exact cause of acne is not fully understood, but it is believed to be due to a combination of factors, including hormonal changes, genetics, and the overproduction of sebum (oil) by the skin's sebaceous glands. Bacteria called Propionibacterium acnes can also contribute to the development of acne.

Symptoms of acne include:

• Blackheads: Open comedones that form when oil and dead skin cells clog the hair follicle and are exposed to air.
• Whiteheads: Closed comedones that form when oil and dead skin cells clog the hair follicle and are not exposed to air.
• Papules: Small, red, raised bumps that can be painful to the touch.
• Pustules: Red, inflamed bumps that contain pus.
• Nodules: Large, painful, solid lesions that develop deep in the skin.
• Cysts: Large, painful, pus-filled lesions that can cause scarring.

Acne can be treated with a variety of medications, including topical and oral antibiotics, retinoids, and benzoyl peroxide. In severe cases, isotretinoin may be prescribed. Good skincare habits, such as regularly washing the face with a gentle cleanser and avoiding picking or squeezing pimples, can also help to prevent the development of acne.