DERMATOLOGY

NAME: MUHAMMAD NOORAIMAN AHMAD NOORDIN

GROUP : 30 A TEACHER’S NAME: SUZANNA ABDULOVNA

PYODERMA, SCABIES & PEDICULOSIS

Definition

• Pyoderma literally means “pus in the skin” and can be caused by infectious, inflammatory, and/or neoplastic etiologies; any condition that results in the accumulation of neutrophilic exudate can be termed a pyoderma. Most commonly, however, pyoderma refers to bacterial infections of the skin

Classification

According to etiology: Staphylococcal Streptococcal Mixed According to depth: Superficial Deep According to character: Acute Chronic

• Pyoderma is a bacterial infection of the skin that can occur in different layers of the skin.

• A superficial pyoderma involves the surface layers of the skin and can often be recognized by the transient presence of pustules (pimples). These pustules often rupture and can leave behind a small crust or a bald spot. Folliculitis is a pyoderma where the bacterial infection is in the hair follicle. If this is present, a pustule, crust or hair loss may be evident.

• Deep pyoderma occurs when the infection is in deeper skin layers, and can sometimes be recognized when pus is expressed from the skin lesions

• The two important pyogenic organisms are the Staphylococcus aureus and the Streptococcus pyogenes.

• Most skin infections are superficial and secondary to a variety of other conditions, most notably allergies (flea allergy, atopy, food allergy), internal diseases (particularly endocrinopathies such as hypothyroidism or hyperadrenocorticism), seborrheic conditions (including follicular or sebaceous gland diseases), parasitic diseases (eg, Demodex canis ), or anatomic predispositions (eg, skin folds). Primary pyoderma occurs in otherwise healthy organisms, without an identifiable predisposing cause, resolves completely with appropriate antibiotics, and is usually due to Staphylococcus intermedius or other staphylococci

The disease can occur on healthy skin, and complicated by a variety of diseases.

Pyoderma is a bacterial infection of the skin that can occur in different layers of the skin.

Superficial Pyoderma

Deep Pyoderma

Superficial Pyoderma

• A superficial pyoderma involves the surface layers of the skin and can often be recognized by the transient presence of pustules (pimples). These pustules often rupture and can leave behind a small crust or a bald spot. Folliculitis is a pyoderma where the bacterial infection is in the hair follicle. If this is present, a pustule, crust or hair loss may be evident.

Deep Pyoderma

• Deep pyoderma occurs when the infection is in deeper skin layers, and can sometimes be recognized when pus is expressed from the skin lesions

Staphylococcus Aureus cause skin infection

Direct infection of skin and adjacent tissues • a. Folliculitis • b. Impetigo • c. Sycosis barbae • d. Furunculosis • e. Carbuncle • f. Hidradenitis Cutaneous disease due to effect of bacterial toxin • a. Staphylococcal scalded skin syndrome • b. Toxic shock syndrome

• Frequent occur as a commensal on skin & also occurs in the nose frequently (in about a third of the population) and the throat less commonly. The occurrence of S. aureus under these circumstances does not always indicate infection.

• S. aureus can infect other tissues when barriers have been breached (e.g., skin or mucosal lining). This leads to furuncles and carbuncles (a collection of furuncles). In infants, S. aureus infection can cause a severe disease - staphylococcal scalded skin syndrome (SSSS).

• S. aureus infections may spread through contact with pus from an infected wound, skin-to-skin contact with an infected person by producing hyaluronidase that destroys tissues, and contact with objects such as towels, sheets, clothing, or athletic equipment used by an infected person. Deeply penetrating S. aureus infections can be severe. Prosthetic joints put a person at particular risk for septic arthritis, and staphylococcal endocarditis (infection of the heart valves) and pneumonia.

Streptococcus pyogenes cause skin infection

Direct infection of skin or subcutaneous

• a. Erysipelas

• b. Impetigo (non bullous)

• c. Ecthyma

• d. Cellulitis

• e. Necrotizing fascitis

Secondary infection

• Infections typically begin in the throat or skin. S. pyogenes infections localized skin infection ("impetigo"). Erysipelas and cellulitis are characterized by multiplication and lateral spread of S. pyogenes in deep layers of the skin. S. pyogenes invasion and multiplication in the fascia can lead to necrotizing fasciitis, a potentially life-threatening condition requiring surgical treatment.

• Infections due to certain strains of S. pyogenes can be associated with the release of bacterial toxins. Throat infections associated with release of certain toxins lead to scarlet fever. Other toxigenic S. pyogenes infections may lead to streptococcal toxic shock syndrome, which can be life-threatening.

• S. pyogenes can also cause disease in the form of postinfectious "nonpyogenic" (not associated with local bacterial multiplication and pus formation) syndromes. These autoimmune-mediated complications follow a small percentage of infections and include rheumatic fever and acute postinfectious glomerulonephritis. Both conditions appear several weeks following the initial streptococcal infection. Rheumatic fever is characterised by inflammation of the joints and/or heart following an episode of streptococcal pharyngitis. Acute glomerulonephritis, inflammation of the renal glomerulus, can follow streptococcal pharyngitis or skin infection.

Superficial Bacterial Infection

• These include superficial bacterial infections such as impetigo, impetigo contagiosa, ecthyma, folliculitis, Bockhart's impetigo, furuncle, carbuncle, tropical ulcer, etc.

Impetigo

• Impetigo is a highly contagious bacterial skin infection most common among pre-school children. People who play close contact sports such as rugby, American football and wrestling are also susceptible, regardless of age. Impetigo is not as common in adults

Classification Impetigo

Bullous impetigo primarily affects infants and children younger than 2 years. • It causes painless, fluid-filled blisters (usually on the trunk, arms and legs). • The skin around the blister is usually red and itchy but not sore. The

blisters, which break and scab over with a yellow-colored crust, may be large or small, and may last longer than sores from other types of impetigo.

Ecthyma is a more serious form of impetigo in which the infection penetrates deeper into the skin's second layer, the dermis. Signs and symptoms include:

• Painful fluid- or pus-filled sores that turn into deep ulcers, usually on the legs and feet

• A hard, thick, gray-yellow crust covering the sores • Swollen lymph glands in the affected area • Little holes the size of pinheads to the size of pennies appear after crust

recedes • Scars that remain after the ulcers heal

Bullous impetigo

Causes

• It is primarily caused by Staphylococcus aureus, and sometimes by Streptococcus pyogenes. According to the American Academy of Family Physicians, both bullous and non-bullous are primarily caused by Staphylococcus aureus, with Streptococcus also commonly being involved in the non-bullous form.

Transmission

• The infection is spread by direct contact with lesions or with nasal carriers. The incubation period is 1–3 days. Dried streptococci in the air are not infectious to intact skin. Scratching may spread the lesions

Diagnosis

• Impetigo generally appears as honey-colored scabs formed from dried serum, and is often found on the arms, legs, or face

Ecthyma

• Ulcerative pyoderma of the skin caused by bacteria such as Streptococcus pyogenes, Pseudomonas and Staphylococcus aureus. Because ecthyma extends into the dermis, it is often referred to as a deeper form of impetigo

Causes

• Causes by insect bites and an ignored minor trauma. • Ecthyma describes ulcers forming under a crusted surface infection.

The site may have been that of an insect bite or of neglected minor trauma.The bacterial pathogens that cause ecthyma are usually Streptococci and Staphylococci. It is treated by antibiotics like cloxacillin, erythromycin and cefalexin.

• Ecthyma has a predilection for children and elderly individuals. Outbreaks have also been reported in young military trainees

• Ecthyma usually arises on the lower extremities of children, persons with diabetes, and neglected elderly patients. During wartime in tropical climates, ecthymatous ulcers are commonly found on the ankles and dorsi of the feet

Transmission

• Ecthyma begins similarly to superficial impetigo. Group A beta-hemolytic streptococci may initiate the lesion or may secondarily infect preexisting wounds. Preexisting tissue damage (e.g., excoriations, insect bites, dermatitis) and immunocompromised states (e.g., diabetes, neutropenia) predispose patients to the development of ecthyma. Spread of skin streptococci is augmented by crowding and poor hygiene.

• The difference between ecthyma and impetigo is that in impetigo the erosion is at the stratum corneum, while in ecthyma the ulcer is full thickness, and thus heals with scarring.

• There is no racial or sexual dominance in Ecthyma

Ecthyma

Folliculitis

• Folliculitis is the inflammation of one or more hair follicles. The condition may occur anywhere on the skin with the exception of the palms of the hands and soles of the feet

Causes

Develop from Staphylococcus aureus and Pseudomonas aeruginosa. Which starts when hair follicles are damaged by friction from clothing, an insect bite, blockage of the follicle, shaving, or braids too tight and too close to the scalp. In most cases of folliculitis, the damaged follicles are then infected with the bacterium Staphylococcus.

Fungal

• Tinea barbae is similar to barber's itch, but the infection is caused by the fungus T. rubrum.

• Malassezia folliculitis, formerly known as Pityrosporum folliculitis, is caused by yeasts (fungi) of the genus Malassezia.

Bacterial

• Hot-tub folliculitis is caused by the bacterium Pseudomonas aeruginosa. The folliculitis usually occurs after sitting in a hot tub that was not properly cleaned before use. Symptoms are found around the body parts that sit in the hot tub—typically the legs, hips, buttocks, and surrounding areas. Symptoms are typically amplified around regions that were covered by wet clothing, such as bathing suits.

• Sycosis vulgaris, Sycosis barbae or Barber's itch is a staphylococcus infection of the hair follicles in the bearded area of the face, usually the upper lip. Shaving aggravates the condition.

• Gram-negative folliculitis may appear after prolonged acne treatment with antibiotics.

Viral • Herpetic folliculitis may occur when Herpes Simplex Virus infection

spreads to nearby hair follicles - mostly around the mouth Non-infectious • Pseudofolliculitis barbae is a disorder occurring when hair curves

back into the skin and causes inflammation. • Eosinophilic folliculitis may appear in persons with impaired

immune systems. • Folliculitis decalvans or tufted folliculitis usually affects scalp.

Several hairs arise from the same hair follicle. Scarring and permanent hair loss may follow. The cause is unknown.

• Folliculitis keloidalis scarring on the nape of the neck, most common among males of curly hair.

• Oil folliculitis is inflammation of hair follicles due to exposure to various oils and typically occurs on forearms or thighs. It is common in refinery workers, road workers, mechanics, sheep shearers. Even makeup may cause it

Symptoms

• rash (reddened skin area)

• pimples or pustules located around a hair follicle – may crust over

– typically occur on neck, armpit, or groin area

– may be present as genital lesions

• itching skin

• spreading from leg to arm to body through improper treatment of antibiotics

Folliculitis

Furuncle / Boil

• It is a deep folliculitis, infection of the hair follicle. Commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Individual boils clustered together are called carbuncles.

• Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.

Causes

• Usually, the cause is bacteria such as staphylococci that are present on the skin. Bacterial colonization begins in the hair follicles and can cause local cellulitis and inflammation. Additionally, myiasis caused by the Tumbu fly in Africa usually presents with cutaneous furuncles.

• Risk factors for furunculosis include bacterial carriage in the nostrils, diabetes mellitus, obesity, lymphoproliferative neoplasms, malnutrition, and use of immunosuppressive drugs. Patients with recurrent boils are as well more likely to have a positive family history, take antibiotics, and to have been hospitalized, anemic, or diabetic; they are also more likely to have associated skin diseases and multiple lesions.

Complications

• The most common complications of boils are scarring and infection or abscess of the skin, spinal cord, brain, kidneys, or other organs. Infections may also spread to the bloodstream (sepsis) and become life-threatening.

S. aureus strains first infect the skin and its structures (for example, sebaceous glands, hair follicles) or invades damaged skin (cuts, abrasions). Sometimes the infections are relatively limited (such as a stye, boil, furuncle, or carbuncle), but other times they may spread to other skin areas (causing cellulitis, folliculitis, or impetigo). Unfortunately, these bacteria can reach the bloodstream (bacteremia) and end up in many different body sites, causing infections (wound infections, abscesses, osteomyelitis, endocarditis, pneumonia) that may severely harm or kill the infected person. S. aureus strains also produce enzymes and exotoxins that likely cause or increase the severity of certain diseases. Such diseases include food poisoning, septic shock, toxic shock syndrome, and scalded skin syndrome. Almost any organ system can be infected by S. aureus.

Furuncle

Carbuncle

• is an abscess larger than a boil, usually with one or more openings draining pus onto the skin. It is usually caused by bacterial infection, most commonlyStaphylococcus aureus. The infection is contagious and may spread to other areas of the body or other people. Because the condition is contagious, family members may develop carbuncles at the same time

Causes

• Often, the direct cause of a carbuncle cannot be determined. Things that make carbuncle infections more likely include friction from clothing or shaving, generally poor hygiene and weakening of immunity. For example, persons with diabetes and immune system diseases are more likely to develop staphylococcal infections.

Presentation

• A carbuncle is made up of several skin boils. The infected mass is filled with fluid, pus, and dead tissue. Fluid may drain out of the carbuncle, but sometimes the mass is so deep that it cannot drain on its own. Carbuncles may develop anywhere, but they are most common on the back and the nape of the neck.

• The carbuncle may be the size of a pea or as large as a golf ball. It may be red and irritated, and might hurt when touched. It may also grow very fast and have a white or yellow center. It may crust or spread to other skin areas. Sometimes, other symptoms may occur, such as fatigue, fever and a general discomfort or sick feeling. Itching may occur before the carbuncle develops

Carbuncle

Treatment

• The primary treatment of superficial pyoderma is with appropriate antibiotics for ≥21 and preferably 30 days. All clinical lesions (except for complete regrowth of alopecic areas and resolution of hyperpigmented areas) should be resolved for at least 7 days before antibiotics are discontinued. Chronic, recurrent, or deep pyodermas typically require 8-12 week or longer to resolve completely.

• First-time bacterial pyoderma can be treated with empiric antibiotic therapy such as lincomycin, clindamycin, erythromycin, trimethoprim-sulfamethoxazole, trimethoprim-sulfadiazine, chloramphenicol, cephalosporins, amoxicillin trihydrate-clavulanic acid, or ormetoprim-sulfadimethoxine.

• Amoxicillin, penicillin, and tetracyline are inappropriate choices for treating superficial or deep pyodermas because they are ineffective in 90% of these cases. Fluoroquinolones should not be used for empiric therapy. Severe deep pyoderma, recurrent pyoderma, or first-time bacterial pyodermas that do not respond to therapy should be treated based on culture and sensitivity.

• Topical antibiotics may be helpful in focal superficial pyoderma. A 2% mupiricin ointment penetrates skin well and is helpful in deep pyoderma, is not systemically absorbed, has no known contact sensitization, and is not used as a systemic antibiotic that would increase the likelihood of cross-resistance. It is not very effective against gram-negative bacteria. This ointment should not be used in cats with any known or suspected history of renal disease because the preparation contains propylene glycol. Neomycin is more likely to cause a contact allergy than other topicals and has variable efficacy against gram-negative bacteria. Bacitracin and polymyxin B are more effective against gram-negative bacteria than other topical antibiotics but are inactivated in purulent exudates.

Scabies & Pediculosis

• Scabies and pediculosis are two arthropod parasitic skin diseases commonly seen in the primary care setting. Although accurate diagnosis, effective treatment, and preventive measures are available, infestations with scabies and lice are pandemic, affecting millions of people worldwide. The primary physician should be able to recognize the manifestations of infestation quickly and treat infestations effectively.

Cause

• Mite (Sarcoptes scabiei hominis) – scabies

• Pediculosis may be divided into the following types:

• Pediculosis capitis (Head lice infestation)

• Pediculosis corporis (Pediculosis vestimenti, Vagabond's disease)

• Pediculosis pubis (Crabs)

Life Cycle

Treatment

A number of medications are effective in treating scabies & pediculosis; however, treatment must often involve the entire household or community to prevent re-infection. Options to improve itchiness include antihistamines

• Permethrin • Permethrin is the most effective treatment for scabies and the

treatment of choice. It is applied from the neck down usually before bedtime and left on for about eight to fourteen hours, then showered off in the morning. One application is normally sufficient for mild infections. For moderate to severe cases, another dose is applied seven to fourteen days later. Permethrin causes slight irritation of the skin, but the sensation is tolerable. The medication, however, is the most costly of topical treatments.

• Ivermectin • Ivermectin is an oral medication shown by many

clinical studies to be effective in eradicating scabies, often in a single dose. It is the treatment of choice for crusted scabies and is often used in combination with a topical agent. It has not been tested on infants and is not recommended for children under six years of age.

• Topical ivermectin preparations have been found to be effective for scabies in adults and are attractive due to their low cost, ease of preparation, and low toxicity.It has also been useful for sarcoptic mange (the veterinary analog of human scabies)