Patho Flashcards
Tinea Corporis
Classification: Dermatophyte (Fungal) Infection
Patho: A Fungal infection that survives on dead keratin.
Transmission: Autoinoculation from other parts of the body. (from tinea pedis or tinea capitis.)
Skin to skin contact with people or animals.
Prevalence: (Geographic) More common in tropical and subtropical regions. All ages. All genders.
Incubation period: Days to months since contact with vector.
Hx Findings: Other family members who have similar lesions.
Contact with animals. Previous use of Topical steroids.
Classification: Dermatophyte (Fungal) Infection
Patho: A Fungal infection that survives on dead keratin.
Transmission: Autoinoculation from other parts of the body. (from tinea pedis or tinea capitis.)
Skin to skin contact with people or animals.
Prevalence: (Geographic) More common in tropical and subtropical regions. All ages. All genders.
Incubation period: Days to months since contact with vector.
Hx Findings: Other family members who have similar lesions.
Contact with animals. Previous use of Topical steroids.
Classification: Dermatophyte (Fungal) Infection
Patho: A Fungal infection that survives on dead keratin.
Transmission: Autoinoculation from other parts of the body. (from tinea pedis or tinea capitis.)
Skin to skin contact with people or animals.
Prevalence: (Geographic) More common in tropical and subtropical regions. All ages. All genders.
Incubation period: Days to months since contact with vector.
Hx Findings: Other family members who have similar lesions.
Contact with animals. Previous use of Topical steroids.
O/E: Scaling, sharply marginated plaques with or without pustules or vesicles. Peripheral enlargement and central clearing, produces annular configuration with concentric rings. Single and occasionally scattered multiple lesions. Mild to severe pruritus.
Location: Areas not defined by other tineas i.e., tinea pedis,
tinea capitis, tinea cruris, etc.
DDX:
Psoriasis
Seborrheic dermatitis
Eczema
Contact dermatitis
Lyme disease
Pityriasis rosea
Tx Plan:
Rx: Clotrimazole 1% cream/Canesten Topical BID X 4 weeks
Pt education: Hygiene, avoid skin to skin contact, loose breathable clothes to allow skin to dry.
Monitor Pt / Re evaluate (RTC) in 1 week or if condition worsens
Tests: Fungal Scraping, Woods Lamp (most cases do not fluoresce)
Refer to MO/PA for long term Tx. Suggest Dermatologist referral in worst cases.
Tinea Cruris
Classification: Dermatophyte (Fungal) Infection.
Patho: A Fungal infection that survives on dead keratin.
Transmission: Autoinoculation from other parts of the body, usually Tinea Pedis.
Prevalence: Any age, but rare in children. More common in males.
Onset: Sub acute/Chronic
Hx Findings: Warm, humid environment:
Tight clothing worn by men;
Possible Obesity.
Chronic topical glucocorticoid application (because of decreased host immunologic local reaction).
Past or current Hx of Tinea Pedis and/or Tinea Cruris
O/E: Usually bilateral,
scaly with red-brown centres (well-demarcated dull red/tan/brown plaques)
Large, scaling, central clearing.
Papules, pustules may be present at margins.
Clearly defined, raised border.
*Pruritus is common (often what has made
Pt seek care).
Location: Groin, pubic regions and thighs.
Unlike yeast infections, the scrotum and penis
are usually spared.
Occasionally the gluteal cleft is affected.
DDX:
Erythrasma (bacterial)
Candida
Psoriasis
chafe
Tx Plan:
Rx: Clotrimazole 1% cream/Canesten Topical BID X 4 weeks, including at least 1 week after lesions have cleared.
Tx co-existing locations of fungal infections (ring worm, tinea unguium and athlete’s foot)
Pt education: Hygiene, avoid skin to skin contact, loose breathable clothes to allow skin to dry. Dry off before putting on clothes. Put on your socks before you put on your underwear.
Monitor Pt / Reevaluate (RTC) in 1 week or if condition worsens
Tests: Fungal Scraping, Woods Lamp (most cases do not fluoresce)
Refer to MO/PA for long term Tx. Suggest Dermatologist referral in worst cases.
TINEA PEDIS (Athlete’s Foot)
Classification: Dermatophyte (Fungal) Infection.
Patho: A Fungal infection that survives on dead keratin.
Transmission: Barefoot walking on floors
Prevalence: males more prominent than females
approx. 4% of population
Rare in children/can be common in teens
Incubation period/Onset: Chronic. Usually between age 20-50
Hx Findings: Months to years
Often prior Hx of tinea pedis, tinea unguium of toenails.
May flare in hot climate
Sweaty feet / Hx of Excessive sweating
Occlusive tightfitting footwear (boots)
Immunosuppression
Prolonged application of topical steroids
O/E: Erythema, scaling, maceration, possible bulla formation and pruritus. Pain with secondary bacterial infection.
4 clinical presentations:
interdigital, moccasin, inflammatory/bullous, ulcerative
Location: Feet (usually bilateral)
DDX: Interdigital type: erythrasma (bacterial), impetigo (bacterial)
Moccasin type: psoriasis vulgaris, eczematous dermatitis (including dyshidrotic eczema)
Inflammatory/bullous type: bullous impetigo, contact dermatitis
Tx Plan:
Rx: Clotrimazole 1% cream/Canesten Topical BID X 4 weeks
Pt education: Hygiene, wear footwear in public showers, washing feet with benzoyl peroxide bar after shower, using antifungal foot powders.
Dry feet. Dry shoes. Change Socks.
Monitor Pt / Reevaluate (RTC) in 1 week or if condition worsens
Tests: Fungal Scraping, Woods Lamp (to rule out erythrasma)
Refer to MO/PA for long term Tx. Suggest Dermatologist referral in worst cases.
4 TYPES DESCRIBED:
Interdigital: (1) dry scaling and (2) maceration, peeling, fissuring of toe webs. Hyperhidrosis common. Most common site: between fourth and fifth toes. Infection may spread to adjacent areas of feet.
Moccasin type: Well demarcated erythema with minute papules on margin, fine white scaling, and hyperkeratosis (confined to the heels, soles, lateral borders of feet).
Inflammatory/bullous type: Vesicles or bullae filled with clear fluid (pus usually indicates secondary infection. Distribution; sole, instep, web spaces.
Ulcerative type: Extension of interdigital tinea pedis onto dorsal and plantar of foot. Usually complicated by bacterial infection.
Non Testable Term (Erythrasma: overgrowth of normal skin bacterium, Corynebacterium minutissimum; presents as bilateral, irregular-shaped, brown plaques with scales found in intertriginous (skinfold) areas.)
TINEA UNGUIUM/ONYCHOMYCOSIS
Classification: Dermatophyte (Fungal) Infection
Patho: A fungal infection that survives on dead keratin
Transmission: Transmission from one individual to another, by fomite or direct contact, commonly among family members
Prevalence: In the US and Europe, up to 10% of the adult population affected
Onset: Children or adults. Chronic without therapy
Hx Findings: Other family members with similar findings.
Risk factors: atopy, diabetes mellitus, Immunosuppressive drugs, HIV/AIDS. For toenail onychomycosis, most important factor is wearing of occlusive footwear
/E: Nail plates may be chalky white or yellow, thickened, cracked, friable and raised by underlying hyperkeratotic debris. Check for concomitant tinea pedis
Location: Approximately 80% of onychomycosis occurs on the feet. Simultaneous occurrence on toenails and fingernails is not common
DDX: Psoriasis,
Eczema
Onychogryphosis
Pincer Nails
Congenital Nail Dystrophies
Tx Plan:
MO Rx: Topical agents (usually ineffective)
Systemic agents (terbinafine). MO Rx Tests: Nail clipping. Direct microscopy / fungal culture.
Refer to MO/PA for long term Tx. Suggest Dermatologist referral in worst cases.
Pt Education: Pt should debride dystrophic nails weekly. Put on socks before underwear to avoid self-transmission.
Cutaneous Candidiasis
Classification: Yeast infection
Patho: Candidiasis is most frequently caused by the yeast Candida Albicans.
Transmission: Normal inhabitant of mucosal surfaces.
Prevalence: Young and old.
Incubation period/Onset: Chronic.
Hx Findings: Many patients have predisposing factors, such as diabetes, poor hygiene and/or obesity.
May be individuals who immerse their hands in water
(cleaners, health care workers, bartenders, florists)
O/E: Intertrigo. Occluded skin.
Erythema, Pruritus, tenderness, pain.
Initial inflammatory papules and pustules on erythematous base become eroded and confluent. Progressing to sharply demarcated erythematous eroded patches with peripheral inflammatory papules and pustules.
Location: Occurs in moist, occluded cutaneous sites.
Inframammary, perineal, intergluteal, interdigital (on feet and hands), under/inside diapers or casts.
DDX:
Interdigital: consider scabies
Intertrigo/occluded skin: erythrasma, dermatophytosis and tinea versicolor.
Diaper dermatitis: atopic dermatitis, psoriasis, irritant and seborrheic dermatitis.
Tx Plan:
Lab: Fungal Culture - IOT identify the species of Candida.
Lab: Bacterial Culture - IOT rule out bacterial infection.
Pt Education; keep areas dry, loose clothing
Rx: Clotrimazole topical cream BID x 2-3 weeks;
(clinical improvement and relief of pruritus usually within first week.)
Refer to MO/PA
RTC if condition worsens or doesn’t improve
TINEAS - LESS COMMON
In comparison to Tinea Corporis, Tinea Cruris, Tinea Pedis and Tinea Unguium/Onychomycosis; the tineas below are relatively rare. However, their definitions are still important to know.
Tinea Capitis: dermatophyte infection of the scalp
Tinea Manuum: dermatophyte infection of the hand(s)
Tinea Facialis: dermatophyte infection of the glabrous facial skin
Tinea Barbae: dermatophyte infection of the androgen-sensitive beard and moustache area
Note that tinea Capitis can be treated with a Med Tech Rx of SELENIUM SULFIDE, LOTION 2.5% (Versel®) or Selsun blue. Often this condition may result in increased dandruff. While rare it is still possible to treat.
PITYRIASIS VERSICOLOR
Classification: Overgrowth of normal flora (yeast)
Patho: Resident cutaneous flora: Malassezia (Pityrosporum Ovale)
Transmission: Infections are not contagious.
Prevalence/Onset: Temperate climates; appears in summertime, affecting 2% of pop; may regress during cooler months. Subtropical and tropical climates: year around in 20% of pop.
Duration: Months to years
Hx Findings: High temperature environment/relative humidity
Hx of oily skin, hyperhidrosis, hereditary factors
Current Rx of glucocorticoid Tx
Immunodeficiency
O/E: Well demarcated scaling macules and patches
Variable pigmentation
Occurring most commonly on the trunk
Occasionally, mild pruritus Macules are sharply marginated, round or oval, varying in size. In untanned skin, lesions are light brown. On tanned skin, white. Can be red.
Pt usually presents @ clinic due to cosmetic concerns
Location: Most commonly on the trunk
DDX:
Vitiligo, pityriasis alba
(Scaling lesions) Tinea corporis, seborrheic dermatitis, pityriasis rosea
Treatment Plan:
Woods Lamp Test: Blue-green fluorescence of scales. May be negative in pts who have showered recently because the fluorescent chemical is water soluble. May be false positive if pt has applied creams. If done properly can detect sub clinical presentation.
PT education: hygiene, dyspigmentation persists for months after infection has been eradicated. Avoid applying skin oils
Refer to MO/PA for long term management of condition. Suggest Derm referral.
Med Tech Rx: Clotrimazole 1% cream/Canesten Topical BID X 4 weeks
Med Tech Rx: Selenium sulfide 2.5% lotion or shampoo (Versel)
RTC if condition worsens or doesn’t improve.
DDX:
Vitiligo, pityriasis alba
(Scaling lesions) Tinea corporis, seborrheic dermatitis, pityriasis rosea
Treatment Plan:
Woods Lamp Test: Blue-green fluorescence of scales. May be negative in pts who have showered recently because the fluorescent chemical is water soluble. May be false positive if pt has applied creams. If done properly can detect sub clinical presentation.
PT education: hygiene, dyspigmentation persists for months after infection has been eradicated. Avoid applying skin oils
Refer to MO/PA for long term management of condition. Suggest Derm referral.
Med Tech Rx: Clotrimazole 1% cream/Canesten Topical BID X 4 weeks
Med Tech Rx: Selenium sulfide 2.5% lotion or shampoo (Versel)
RTC if condition worsens or doesn’t improve
HERPES SIMPLEX VIRUS/HERPES LABIALIS
Classification: Viral
Patho: HSV persists in sensory ganglia for the life of the Pt.
Transmission: Mostly occurs when persons shed virus but lack symptoms or lesions. Usually skin-skin, skin-mucosa, mucosa-skin contact.
Duration: Resolve in 2-4 weeks..
Recurrence: 1/3 of persons with herpes labialis will have a recurrence; of these, ½ will have 2 recurrences annually.
Hx Findings: skin/mucosal irritation, fever common cold,
altered hormones (menstruation), altered immune state
O/E:
primary infections; usually asymptomatic or have trivial symptoms.
characterized by vesicles at the site of inoculation
regional lymphadenopathy,
Fever, H/A, malaise.
Recurrent; Prodrome of tingling, itching, or burning usually precedes any signs by 24hrs.
Systemic symptoms are usually absent. Erythema initially, pustules, erosions (may enlarge into ulcerations), which may be crusted or moist. Grouped vesicles on erythematous base – erosions and crusts.
Location:
Usually, the original site of inoculation
Labial (lips), periorbital, distal fingers, genitalia
DDX:
Primary intraoral HSV infection;
Aphthous stomatitis
hand-foot-mouth disease
Recurrent lesion;
fixed drug eruption
Tx Plan:
Test: viral culture or antigen detection
PT education: Prevention; skin-skin contact should be avoided during outbreak.
Refer to MO/PA
Antiviral Rx: Valacyclovir (Valtrex). Topical antiviral therapy is minimally effective.
Rx: Analgesics
wet dressings (water, saline, burrow’s sol.) for pt discomfort.
RTC PRN
HERPES – VARICELLA ZOSTER VIRUS (Shingles)
Classification: Dermatomal viral infection
Patho: Reactivation of the varicella-zoster virus due to diminished immunity to it.
The virus establishes latent infection in ganglia lasting for life.
Transmission: 99.999% of population infected.
Prevalence: 66% are >50 years of age.
Onset: Acute. Triggered by immunosuppression, trauma, tumor, or irradiation. Duration: Chronic
Hx Findings: Previous chicken pox
Herpes Zoster (shingles): is an acute dermatomal infection associated with reactivation of the varicella-zoster virus (varicella or chickenpox) and is characterized by unilateral pain and a vesicular or bullous eruption limited to a dermatome(s) innervated by a corresponding sensory ganglion. The major morbidity is post herpetic neuralgia (PHN).
Nearly 100% of adults are seropositive for VZV antibodies by their 30’s. Immunization to VZV in childhood will alter the epidemiology of HZ.
Risk factors: the most common factor is diminishing immunity to VZV with advancing age.
HIV-infected individuals have an eightfold increased incidence of HZ.
In most cases triggering factors are not known.
Varicella passes the VZV from lesions in the skin and mucosa to sensory ganglia via sensory fibers. In the ganglia the virus establishes latent infection lasting for life. Reactivation occurs in those ganglia in which VZV has achieved the highest density and is triggered by immunosuppression, trauma, tumor, or irradiation. Reactivated virus can no longer be contained. Virus multiplies and spreads down the sensory nerve to the skin/mucosa where it produces the characteristic vesicles.
DEFINITION:
Postherpetic neuralgia is a nerve pain due to damage caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster (commonly known as shingles) in that same dermatomic area. The neuralgia typically begins when the herpes zoster vesicles have crusted over and begun to heal.
Teaching point #4, Tpt 4 1. (q-u). (Viral infection) herpes; simplex, labialis and zoster. Aphthous stomatitis and acne.
(Ref: C069; pg. 821-827, 798-815, 802-805, 1016-1018, 2-7 & C434; pg.881-887, 576-594)
O/E: Unilateral
Papules within 24 hrs
Vesicles-bullae appear in 48 hrs,
pustules in 96 hrs,
crust in 7-10 days.
New lesions will continue to appear for up to 1 week.
Erythematous, edematous base with superimposed clear vesicles, sometimes hemorrhagic.
Pain
Location: Dermatomal: 2 or more neighbouring dermatomes may be involved
Thoracic (>50%),
Trigeminal (10-20%),
Lumbosacral (10-20%)
Cervical (10-20%).
Non-adjacent dermatomal zoster is rare.
3 clinical stages: prodromal, active, and chronic.
Symptoms:
Prodromal Stage: headache, fever, malaise.
Skin: Pain (stabbing, pricking, sharp, boring, penetrating, shooting, lancinating, shooting, tenderness, paresthesia (itching, tingling, burning, freeze-burning) in the involved dermatome(s) precedes the eruption.
Active Vesiculation: headache, fever, malaise.
Skin: lesions may be pruritic, lesions themselves not painful.
Chronic stage: depression is very common.
Skin: PHN (burning, ice-burning, shooting), can persist for weeks, months, or years after lesions have resolved.
Some scarring is very common after healing of HZ.
DDX:
Prodromal stage: mimics migraine, cardiac or pleural disease
Active vesiculation: HSV, ACD (poison ivy/oak), ICD.
Tx Plan:
Refer to MO/PA
ECG; to rule out cardiac if chest pain is present.
Imaging; to rule out organic, pleural, pulmonary, or abdominal diseases.
Relieve constitutional symptoms, minimize pain, prevent secondary infection, speed crusting of lesions and healing and ease discomfort.
Rx: Antiviral therapy for Valacyclovir (Valtrex) 1000mg PO tid for 7 days
Rx: Analgesics PRN; NSAIDs, (T3),
Moist dressings (Water, saline, Burrow’s sol.)
Bed rest, sedatives PRN
RTC for follow up
HUMAN PAPILLOMA VIRUS (HPV)
Classification: Viral
Patho: Infect squamous epithelia of skin and mucous membranes.
Transmission: Skin-to-Skin.
Breaks in the stratum corneum facilitate transmission.
Prevalence: Widespread to ubiquitous.
Duration: Chronic. Persists for several years if untreated.
Hx Findings: Close contact to others with an infection
Exposure to floors/surfaces and others with HPV
A hx of skin/derm trauma
Classification: Viral
Patho: Infect squamous epithelia of skin and mucous membranes.
Transmission: Skin-to-Skin.
Breaks in the stratum corneum facilitate transmission.
Prevalence: Widespread to ubiquitous.
Duration: Chronic. Persists for several years if untreated.
Hx Findings: Close contact to others with an infection
Exposure to floors/surfaces and others with HPV
A hx of skin/derm trauma
DDX:
Hands: molluscum contagiosum, seborrheic keratosis.
Feet: callus, corn (clavus) have no thrombosed capillary loops
Tx Plan:
Plantar wart pads help relieve pressure and pain
Med Tech Rx: Liquid Salicylic acid (Soluver Plus) applied directly to lesion daily with close monitoring and in combination with debriding the wart with an emery board or pumice stone to improve effectiveness of Tx.
Med Tech Rx: Cryogenic Tx done on wart parade by Med Tech or MO, aggressive Tx can resolve the matter in 1-2 applications. MO must do initial Dx.
RTC for re-assessment
Pt education: Footwear in public showers. Change socks if plantar. Don’t pick at warts with fingernails.
Ref.: C069, 8th ed. p. 658-665 TBC
PT EDUCATION NOTES:
DO NOT PICK AT WARTS. Can infect skin under nails. Almost impossible to treat. Creates deformed nails.
IRT emery board or pumice stone: do not debride until it bleeds. Do not re use same device for other areas on foot.
TX NOTES:
Salicylic Acid is an effective keratolytic that causes a slow destruction of the virus infected epidermis.
Liquid nitrogen burn/frostbite aftercare should be conducted. Often causes scarring.
FOLLOW UP: RTC – when re-examined the return of fingerprints is a sign of resolution of the wart.
HPV – VERRUCAE VULGARIS (COMMON WARTS)
O/E: Firm papules
1 to 10 mm or rarely larger
Hyperkeratotic
Clefted surface
Palmar lesions disrupt the normal line of fingerprints
Characteristic “red or brown dots” are thrombosed capillary loops
Isolated lesion, scattered discrete lesions
Annular at sites of prior therapy
Location: Occur at sites of trauma
Hands
Fingers
Knees
HPV – VERRUCAE PLANTARIS (PLANTAR WARTS)
E: Early small, shiny, sharply marginated hyperkeratotic papule/plaque with brown-black dots (thrombosed capillaries). Confluence of many small warts results in a mosaic wart.
Lesions may occur on opposing surfaces of two toes. Tenderness may be marked, especially lesions over pressure points. Location: Plantar aspect of feet Often at heads of metatarsals Heels and toes
IMPETIGO
Classification: Bacterial
Patho: Group A streptococcus or Staphylococcus aureus infection of epidermis.
Transmission: From shared towel, cup or glass . Family members. Pets.
Prevalence: Primary infections are most common in children.
Secondary infection, common at any age.
Duration: Lesions last days to weeks
Hx Findings: Living and working in high humidity.
Pre-existing skin cond. (scabies, atopic dermatitis, etc.)
Elderly, Soldier, Alcoholic, diabetic
Poor hygiene
crowded living conditions
neglected minor traumas
Other family members with Impetigo.
Other children at daycare/school.
O/E:
Variable pruritus
Especially associated with atopic dermatitis.
Vesicles and bullae containing clear yellow or slightly turbid fluid
Little to no surrounding erythema
Bullous arising on normal-appearing skin.
With rupture, bullae decompress.
If roof of bullae is removed, shallow moist erosions form.
Honey golden-yellow crusting
Often non painful
Location:
Site of neglected wounds
Traumatic breaks in epidermis
Bug bites
DDX:
ACD
ICD
Seborrheic dermatitis
Herpes
Scabies
Insect bites
Tx Plan:
Test: Gram stain, culture
Pt education: recurrence can occur by recolonization from a family member or a family dog. Daily bath. Bedding, clothing, towel changes each day for first two days of Rx use. Frequently use ethanol or isopropyl hand sanitizer. Don’t pick at wound.
MO Rx: Benzoyl peroxide wash (bar).
MO Rx: Topical antibiotics; Mupirocin TID 7-10 days.
MO Rx: Oral antibiotics; type according to test results
Check family members for signs of impetigo.
Refer to MO/PA for Rx and Test Req.
RTC if condition worsens or does not resolve with Tx
Cellulitis
Classification: Bacterial
Patho: Infection of dermal and subcutaneous tissues.
Often Group A Streptococcus (Can be many others)
Transmission: Usually penetrating injury or Hx of break in skin barrier.
Prevalence: Any age
Incubation period: Acute onset. Incubation period of a few days
Hx Findings: Underlying dermatological disorders
Trauma (bites, abrasion, burns, laceration, etc.)
Surgical wound
Mucosal infection
Injection drug use
Malaise
Anorexia
Fever
Chills can develop rapidly before cellulitis is apparent.
Cellulitis:
Has many of the same features of erysipelas but extends into the subcutaneous tissues.
The morbidity and mortality rates are significant. (likely due to sepsis)
Erysipelas:
A distinct type of superficial cutaneous cellulitis with marked dermal lymphatic involvement, painful, bright red, raised, edematous, indurated plaque with advancing raised borders.
Cellulitis: Erysipelas and cellulitis are acute, spreading infections of dermal and subcutaneous tissues, characterized by a red, hot, tender area of skin, often originating at the site of bacterial infection caused most frequently by Group A Streptococcus (GAS). But can be S. aureus, and Group B.
O/E:
Tissue feels hard on palp
Extremely painful
Red, Hot, edematous
Shiny plaque, and very tender.
Migratory borders as infection spreads, irregular, and slightly elevated.
Vesicles, bullae, erosions, abscesses, hemorrhage and necrosis may be present
Usually unilateral on limbs
Fever
Signs of sepsis
Location:
lower leg most common site
following interdigital tinea
Arm in young males
IV drug use site
Post mastectomy site
trunk operative wound site
Eye (complication of conjunctivitis)
DDX:
Deep vein thrombosis
Stasis dermatitis
Contact dermatitis
insect bite
fixed drug eruption.
Tx Plan:
REFER TO MO/PA: Condition must be referred promptly.
Rx: Antibiotics in accordance with diagnostic test results.
Marking size with surgical pen to monitor changes
PEDICULOSIS (Lice)
Classification: Parasite
Patho: Infestation of sucking lice (1-3mm in size) (nits <1 mm)
Lay their eggs on hair shafts or in seams of clothing
Female lives for up to 3 months
Can lay 300 eggs (nits) in her lifetime
Feed multiple times daily
Transmission: Most commonly by direct contact with bedding, brushes, or clothing, according to the type of louse.
Prevalence: Hundreds of millions of cases worldwide yearly.
Hx Findings: Pt may be aware symptoms in close contacts.
Common S/S: Pruritus
3 Types of Lice:
Pediculosis Capitis (Head lice): is an infestation of the scalp. The lice feed on the scalp and neck and deposit its eggs on the hair.
Pediculosis Corporis (Body lice): remain on clothing except when feeding, unable to survive more than a few hours away from the host. (Body structure and size are similar to Head Lice)
Pediculosis Pubis (Pubic lice): an infestation of hair-bearing regions most commonly the pubic area, but at times the chest, axillae and the upper eyelashes.
Physiology:
Pediculosis and scabies may co-exist in the patient.
Symptoms: Pruritus.
Phase 1: none,
phase 2: popular urticaria with moderate pruritus,
phase 3: Wheals following bite with delayed papules and intense pruritus, and
phase 4: smaller papules and mild pruritus. The phases are related to patient sensitivity.
Location: Head Hair
Prevalence: Girls > boys, 3-11 years, but can infect all ages.
More common in Caucasian vs African American
Uncommon in Africa
Transmission: Shared hats, brushes.
Direct contact.
Schools are the most common
areas for infestations.
On Exam: Lice are identified by eye or with a lens.
Lay eggs(Nits) 1-2mm from scalp on hair shaft
Longer standing infestations may be 15cm from the scalp
New eggs are a creamy-yellow colour, and empty eggshells are white.
Lesions apparent on the neck
Pruritus of the back and sides of scalp. Rarely infect beards Can infect eye lashes (rare)
Often symptomless aside from Pt Mental health/Consternation.
Unique Symptoms: Pruritus of the back and sides of scalp.
Survival Time: Pediculosis capitis survive for up to 55 hrs off of scalp.
Vector for: Not a significant vector of disease in humans.
SCABIES
Classification: Parasite
Patho: Mite infestation
Transmission: Spread by skin-to-skin contact.
Indirect (via clothing/bedding)
Remain alive >2 days on clothing or bedding
Prevalence: Epidemic in 3rd world countries. Approx. 1/24 people worldwide
Incubation: Onset of pruritus varies with immunity to mite.
1st infestation, about 21 days;
re-infestation, 1-3 days
Duration: Weeks to months unless treated
Incubation period/Onset: Acute.
Hx Findings: Pruritus. Symptoms in close contacts.
O/E: Uncontrolled pruritus (intense widespread)
Often with minimal cutaneous findings apart from secondary excoriations. Itching often interferes with or prevents sleep.
Often present in family members or troops living in close quarters.
Rash; ranges from no rash to generalized erythroderma
Gray or skin-colored ridges 0.50-1cm in length, either linear or wavy with a minute papule or vesicle at the end of the tunnel (burrow).
Pustules if secondary infection.
Location: commonly webspaces at hands, wrists, axillae, buttocks, waistline.
DDX:
Adverse cutaneous drug reaction
Atopic dermatitis
Contact dermatitis
Tx Plan:
Test: skin scraping for visual confirmation under microscope
PT Education: Treat spouse/sexual partner, children, anyone who has close physical contact. Pruritus often persists up to several weeks after successful eradication of mite infestation.
Refer to MO/PA, inform PMed
Rx: Permethrin 5% cream (Nix) to apply neck to toe, leave on for 8-12 hrs, then wash thoroughly. (Retreat in 1 week)
RTC if condition worsens or doesn’t improve
ECZEMA
Eczema – there are many etiologies and a wide range of clinical findings
Acute Eczema – characterized by pruritus, erythema and vesiculation
Chronic Eczema – characterized by pruritus, xerosis, lichenification, hyperkeratosis/scaling +/- fissuring
.
ECZEMA - ATOPIC DERMATITIS (AD)
Classification: Hypersensitivity Reaction.
Patho: IgE mediated/Hypersensitivity reaction.
Transmission: Genetic. 60% of adults with AD had children
with AD and 81% when both parents had AD.
Prevalence: 7-15% of Scandinavian/German.
Onset: 2-12mo: 60%
1-5 yr.: 30%
5yr – adult: 10%
Duration: months or years (untreated)
Hx Findings: Family and/or personal Hx of AD.
Allergic rhinitis and/or asthma
Eliciting Factors: Skin dehydration (bathing/hand washing) inhalants, foods, skin barrier disruption, infections, season, clothing, emotional stress, sweating, pregnancy, menstruation, thyroid …
/E:
Dry skin
Pruritus
In Acute cases: poorly defined erythematous patches, papules, and plaques +or- scale. Edema with widespread involvement; skin appears puffy. Erosions: moist, crusted.
In Chronic cases: lichenification; from repeated rubbing or scratching. Fissures: painful, especially in flexures, on palms, fingers, and soles. Alopecia from scratching and rubbing.
Location: Flexures, front and sides of neck, eyelids, forehead, wrists, and dorsa of the feet and hands. Generalized in severe cases
DDX:
Seborrheic dermatitis
Irritant and allergic contact dermatitis
Psoriasis
Dermatophytosis (tineas)
Tx Plan:
Tests: Bacterial and viral cultures: rule out herpes simplex virus in crusted lesions.
Blood work
Pt education:
Avoid exacerbating factors; avoid rubbing and scratching.
Use mild soaps, emollients PRN several times daily, barrier cream, wet compresses 20 mins 4-6/day (water, saline, Burrow’s)
Refer to MO/PA
Rx: Topical steroids; betamethasone (Betaderm) or hydrocortisone.
Rx: Diphenhydramine for difficulty sleeping due to pruritus
RTC PRN
ECZEMA - CONTACT DERMATITIS - IRRITANT CONTACT DERMATITIS (ICD)
Classification: Acute or chronic inflammatory reaction
Patho: Exposure of the skin to a chemical or other physical agents that can irritate the skin, acutely or chronically. Chronic cumulative exposure to one or more irritants.
Transmission: Chemical/Agent contact with skin.
Prevalence: most common form of occupational skin disease (80%)
.
Onset: Immediate or delayed onset after exposure
Duration: Days, weeks
Hx Findings: Application of a substance
Hx of atopic dermatitis
Possible mechanical irritation
Occlusion
O/E: Lesions
Sharply demarcated erythema and superficial edema
Range from erythema to vesiculation and caustic burn with necrosis
Burning, stinging, painful at site.
Location: The hands are the most affected area.
Cutaneous findings depend on contact with irritant
Lesions do not spread beyond the site of contact
DDX: Allergic Contact Dermatitis (ACD)
Tx Plan: Identify and avoid irritant. Wet compresses 20 mins 4-6/day (water, saline, Burrow’s)
Vesicles/bullae may be drained, tops shouldn’t be removed.
Test: Patch test to rule out Allergic Contact Dermatitis
Pt Education: Avoid irritant; PPE (mask, goggles, gloves, apron), wash immediately after accidental exposures IOT neutralize. Avoid touching and scratching affected area.
Rx: Barrier creams, if occupational ICD persists despite adherence to preventative measures, change of job may be required.
Rx: Topical steroids; Betamethasone (Betaderm) or Hydrocortisone.
Refer to MO/PA
Rx: Diphenhydramine for difficulty sleeping due to pruritus
RTC if condition worsens or doesn’t improve
ECZEMA - ALLERGIC CONTACT DERMATITIS (ACD)
Classification: Cell-mediated hypersensitivity.
Patho: 1st exposure will not result in lesions; however after the required amount of time for sensitization has passed subsequent exposures will result in ACD.
Transmission: Allergen specific.
Prevalence: Allergen specific.
Onset: 48h to days after exposure
Hx Findings: A recent exposure to an allergen.
A previous exposure with a now increased response.
O/E: Pruritus, stinging and pain.
Site of the eruption is limited to the site of exposure. However, it spreads beyond the actual site of exposure with increased sensitivity .
Acute: well-demarcated erythema and edema, closely spaced vesicles, and/or papules;
severe reactions: bullae, confluent erosions exuding serum, and crusts.
Sub-acute: plaques or mild erythema showing small, dry scales, sometimes with red, pointed or rounded, firm papules.
Chronic: plaques of lichenification, scaling with satellite,
small, firm, rounded or flat-topped papules, excoriations,
erythema, and pigmentary alteration.
Location: Depends on exposure
ECZEMA - CONTACT DERMATITIS - ALLERGIC CONTACT DERMATITIS (ACD)Poison Ivy/Poison Oak/Wild Parsnip
Classification: Toxicodendron/Rhus genus plants
Pathology: urushiol creates a complex protein in the skin.
Duration: Indefinitely antigenic!
Prevalence: 50% of people develop S/S. Severity varies.
Onset: Immediate: 4hrs-4days Sensitization after 7-10 days.
Re-exposure: 8 hours to 2 days.
O/E: Characterized by linear arrangement of erythema, papules, vesicles/bullae. Pruritus and edema.
Location: Depends on exposure. Military members often get this on ungloved hands, forearms, chest, abdomen, groin, knees from lying down in the dark.
Tx Plan: Wash kit separately from others. Avoid public washing machines. Use regular laundry detergent and hottest water possible.
DDX: Shingles (may appear to follow a dermatome) any CD
DDX:
Atopic dermatitis
Irritant Contact Dermatitis (ICD)
Seborrheic dermatitis
Psoriasis
Fixed drug eruptions
Tx Plan:
Patch Test to verify allergen
Pt education: Identify and avoid allergen, to avoid touching and scratching. Wash area: Use mild soaps, Wet compresses 20 mins 4-6/day (water, saline, Burrow’s),
Vesicles may be drained; tops shouldn’t be removed.
Refer to MO/PA
Rx: emollients PRN several times daily, barrier cream in mild cases.
Rx: Topical steroids; Betamethasone (Betaderm) or Hydrocortisone.
Rx: Diphenhydramine for difficulty sleeping due to pruritus
RTC if condition worsens or doesn’t improve
ECZEMA - Seborrheic dermatitis
Classification: A chronic eczematous dermatitis associated with lipophilic yeast (pityrosporum ovale).
Patho: normal human cutaneous flora
Transmission: Non contagious.
Prevalence: hereditary, stress increases flares,
HIV infected pers. 2-5% of population.
More common in males.
More common in winter/ less in summer
Incubation period/Onset: Gradual onset.
Infancy (Within first month), puberty,
most between 20-50yrs or older.
Hx Findings: Pruritus is variable, often increased with perspiration.
O/E: Orange-red or grey-white sharply marginated macules or papules/patches or plaques with ‘greasy’ yellow- white scale.
Sticky crusts and fissures are common in the folds behind the ears. On the scalp there is mostly marked scaling. Scattered, discrete on the face and trunk.
Location: Scalp, hairy areas of face and trunk (sternal) and or behind ears.
Sub mammary. Umbilicus.
Genitalia.
DDX:
Mild psoriasis vulgaris,
Impetigo,
Tinea (capitis, corporis, versicolor, faciei)
Tx Plan:
Chronic disorders require initial and maintenance therapy.
Pt education;
Frequent cleansing with shampoo IOT to eliminate dirt and oil.
Dandruff: May improve in moist environment
Seborrhea: Discontinue aggravating factors and reduce stress.
Rx: 2.5% selenium sulfide shampoo/lotion (Selsun Blue) twice a week or as directed. Can be used on areas other than hair.
UV Radiation (sunlight)
Refer to MO/PA for Rx of corticosteroids (2.5% hydrocortisone)
RTC if condition worsens or doesn’t improve.
PSORIASIS
Classification: Immune mediated disorder
Patho: Abnormality of cell kinetics of keratinocytes, resulting in 28 X the production of epidermal cells.
Transmission: Noncontagious. Hereditary
Prevalence: 1.5-2% of western population. Nonspecific to gender
Onset: usually age 20-30 and 50-60. (in children the mean age of onset is 8).
Hx Findings: Chronic, recurring, scaling papules and plaques.
Family history
Trigger Factors: physical trauma is a major factor in eliciting lesions (rubbing and scratching), stress a factor in flares as high as 40% in adults and higher in children, infections, drugs and alcohol ingestion.
O/E: Clinical presentation varies in individuals from presenting with only a few localized plaques or with generalized skin involvement. Lesion is sharply marginated erythematous papule (or dull-red plaques)with a silver-white scale. Scales are lamellar, loosely adherent, and easily removed by scratching.
Location: Elbows, knees, sacral-gluteal region, scalp, palms/soles.
DDX:
Small scaling plaques: Seborrheic Dermatitis, Tinea Corporis.Large geographic areas: Tinea Corporis.Scalp psoriasis; Seborrheic Dermatitis, Tinea Capitis.Nails: Onychomycosis.
Tx Plan:
Refer to Dermatologist
Pt education; Avoid triggers (stress)
Refer to MO/PA (non self limiting)
Photo therapy (get sun… but avoid a sun burn!)
Trunk and extremities: Topical corticosteroid such as betamethasone.
Scalp mild: Medicated shampoos and lotions
Derm consult for additional topicals, phototherapy, oral agents, immunobiologics.
ACNE
Classification: Inflammatory / foreign body response
Patho: Inflammation of the pilosebaceous units of face and trunk.
Transmission: Non Contagious.
Prevalence: Very common, affecting approx. 85% of young people.
Onset: Puberty
O/E: Comedones (closed / open), pustules, papules, nodules, cysts
Possible Hx Findings:
Drugs; Lithium, glucocorticoids, oral contraceptives, androgens (testosterone).
Emotional stress.
Occlusion and pressure on the skin; very important and often overlooked exacerbating factor (acne mechanica)
Background scarring may be present (Face, neck, shoulders, chest back)
DDX:
Folliculitis
Rosacea
Acne-like conditions (steroid acne, drug-induced acne)
Tx Plan (Mild Acne):
The goal is to remove the plug, reduce sebum production and treat bacterial colonization.
PT education; Advise no cure for acne, only treatment for lesions, wash BID with mild soaps,
Rx: Benzoyl peroxide gel 5% once daily or BID (Consult with MO/PA for long term Tx plan)
RTC PRN for booked appt
Refer to MO/PA for (Mild Acne) following suggested Rx : MO Rx:Topical Antibiotics and Topical Retinoids Refer to MO/PA for (Moderate to Severe Acne) following suggested Rx : MO Rx: Oral antibiotics or Accutane
NEVUS (MOLE)
Classification: SUSPICIOUS LESION
Pathophysiology: proliferation of melanocytes within the epidermis,
dermis or both
Clinical Features: asymptomatic, appear in childhood,
some may arise in adulthood
3 Subtypes:
Junctional (melanocytic proliferation is intraepidermal) *see Figure B
Compound (melanocytic proliferation is both intraepidermal and dermal) *see Figure A
Dermal (melanocytic proliferation is intradermal) *see Figure C
Specific Tests: apply the ABCDEs
DDX: Solar Lentigo/Seborrheic Keratosis
Dysplastic Nevus
Melanoma
Pigmented Basal Cell Carcinoma
Tx Plan: Refer to MO/PA
In case of doubt when malignancy cannot be excluded, excise lesion with a narrow margin
SEBORRHEIC KERATOSIS
Classification: SUSPICIOUS LESION
Patho: proliferation of monomorphous keratinocytes and melanocytes
Prevalence/Onset: hereditary, onset around age 30, vary from a few scattered lesions to hundreds
Hx Findings: evolve over months to years, warty generally pigmented ‘stuck on’ greasy papules and plaques, rarely pruritic
O/E: (Isolated or generalized. Face, trunk, extremities.)
Early; Small 1-3mm, barely elevated, later a larger plaque with or without pigmentation. Surface has a greasy feel; often stippling texture like a thimble is noticeable with a hand-lens.
Late; plaque with warty surface and “stuck-on” appearance, “greasy”. Size 1-6cm, brown, gray, black, skin-coloured, round or oval.
DDX: Pigmented basal cell carcinoma or malignant melanoma
Tx Plan: Refer to MO/PA
ACTINIC KERATOSIS
Classification: SUSPICIOUS LESION
Patho: Keratinocyte damage by UVR
Prevalence: Males
Onset: Months to years
Hx Findings: Habitually sun-exposed skin , Adult Pt
O/E: (Face, ears, neck, forearms, hands, shins and scalp)
Adherent hyperkeratotic scale, which is removed with difficulty and pain.
May be papular. Skin-coloured, yellow-brown, or brown; often there is a reddish tinge. Rough like sandpaper. Usually less than 1cm diameter, oval or round.
DDX: Seborrheic keratosis, flat warts, SCC, BCC
Tx Plan: Prevention: Sunscreen. Refer to MO/PA
SQUAMOUS CELL CARCINOMA
Classification: SUSPICIOUS LESION
Prevalence: Increased incidence with UVR, HPV, arsenic, tar, chronic heat exposure, chronic radiation dermatitis
Hx Findings: non-healing generally slowly evolving keratotic or eroded papule/plaque/nodule; especially when occurring on sun damaged skin, on the lower lip, in areas of radiodermatitis or in old burn scars
O/E: sharply demarcated solitary papules or plaques, which may be scaling or hyperkeratotic . Lesions are pink or red. Often asymptomatic but may bleed. May have small erosions and can be crusted.
DDX: eczema, psoriasis, seborrheic keratosis
Tx Plan: Refer to MO/PA; surgical excision, cryosurgery
BASAL CELL CARCINOMA
Classification: SUSPICIOUS LESION
Prevalence: > than 400, 000 new cases/year in USA
rare in brown or black skinned persons.
Hx Findings: > 40 yrs. Male > Female, Caucasian. Heavy sun exposure in youth or x-ray therapy for acne increases risk for BCC.
O/E: nodular, ulcerating, sclerosing, superficial multicentric or pigmented subtypes.
DDX: if pigmented type – melanoma
if nodular or superficial multicentric type – SCC
if ulcerated type – other ulcer etiologies
Tx Plan: Refer to MO/PA
MELANOMA
Classification: SUSPICIOUS LESION
Patho: malignant transformation of melanocytes
Prevalence: lifetime risk is 1-50
Incubation period/Onset: epidemiologic studies demonstrate a role for genetic predisposition and sun exposure in melanoma development. Melanoma is among the most common type of cancer in young adults
Hx Findings/Risk Factors:
-genetics
-light/fair skin
-family history of dysplastic nevi or melanoma
-personal history of melanoma
-UV radiation
-number and size of melanocytic nevi
-congenital nevi
-dysplastic nevus syndrome
O/E: Apply the ABCDEs
A- asymmetry
B- border
C- colour
D- diameter
E- evolution
DDX: Seborrheic Keratosis
Pigmented BCC
Melanocytic Nevus/Dysplastic Nevus
Hemangioma
Six Signs of Malignant Melanoma (ABCDE Rule)
Asymmetry: in shape – One-half unlike the other half.
Border: is irregular-edges irregularly scalloped, notched.
Color: is not uniform; mottled-haphazard display of colors; all shades of brown, black, gray, blue, red and white.
Diameter: is usually large-greater than the tip of a pencil eraser ( 6 ;mm).
Evolution: A history of an increase in the size of lesion is one of the most important signs of malignant melanoma.
Sunburn
Patho: an acute, delayed and transient inflammatory response of normal skin after exposure to ultraviolet radiation or artificial sources
Clinical Features: characterized by erythema, and if severe, by vesicles and bullae, edema, tenderness and pain. Strictly confined to areas of exposure (can occur in areas covered with clothing depending on the degree of UV transmission through fabric). In severe cases, the patient may exhibit weakness, lassitude and a rapid pulse.
Management:
Topical – cool wet compress and topical corticosteroids
Systemic – NSAIDs
*If very severe, patient may require hospitalization for fluid replacement and prophylaxis of infection
INGROWN TOENAIL (onychocryptosis)
Patho: Nail edges that curve and grow into the surrounding tissues.
Soft tissue that has been penetrated becomes irritated and inflamed.
Prevalence: Predominant between 10-30yrs of age.
Onset: Chronic.
Hx Findings: Heredity
improper trimming
trauma
toe crowding in footwear
O/E: Localized pain of the soft tissue surrounding the toenail.
Tenderness.
Erythema
Inflammation
Abscess formation may also be present.
Possible signs of infection.
Toe box of usual footwear may be confined.
Shoes may be improper size.
Location: Usually the big toes
DDX:
Localized Cellulitis
Tx Plan:
Non-surgical TMTs; If infection is not present at the time of presentation, elevation of nail and place cotton or a splint between nail and fold or apply a nail brace.
Pt Education: Cut nails straight across; allow corners of nails to extend beyond the skin and stretch skin folds daily. Avoid tight footwear.
Rx: Epsom foot baths may reduce pain and swelling.
Rx: Analgesics PRN
Rx: Topical Polysporin TID x 7days
Refer to MO/PA for surgical Tx (remove a small spicule of the nail or a nail recession.)
Refer to MO/PA for referral to Specialist(Podiatrist)
RTC if condition worsens or doesn’t improve.
ALOPECIA: The loss of some or all hair in an area.
BULLA: A circumscribed elevated superficial cavity containing fluid.
EDEMA: Swelling caused by excess fluid trapped in the body’s tissues.
ERYTHEMA: Flushing of the skin due to the dilation of blood capillaries in the skin
EROSION: An eating away of a surface due to physical or chemical process including those associated with inflammation.
EXCORIATION: Lesions caused by scratching or picking at skin.
CARBUNCLE: Clusters of furuncles connected subcutaneously, causing deeper suppuration and scarring.
COMEDONES (OPEN): Blackheads
COMEDONES (CLOSED): Whiteheads
CRUSTING - Varying colors of liquid debris (serum or pus) that has dried on the surface of the skin.
EXCORIATION: Areas where the skin has been scraped off or abraded
FISSURE: A linear cleavage of skin, often extending into dermis. Often from cracked dry skin
