dermatological infections

1. DERMATOLOGICAL
INFECTIONS
PREPARED BY: LUBABAH

2. Definition
A skin infection is a condition where bacteria or other germs enter the skin through a wound
and spread, causing pain, swelling, and discoloration.

3. CAUSES OF SKIN INFECTION
Bacterial: Cellulitis, Abscess and impetigo
Viral: Shingles, warts, and herpes simplex
Fungal: Athlete's foot and yeast infections

4. Bacterial infections
FOLLICULITIS, ABSCESS, IMPETIGO, CELLULITIS, ERYSIPELAS

5. FOLLICULITIS, FURUNCULOSIS, AND
CARBUNCULOSIS
Folliculitis is a superficial infection of the hair follicles characterized by erythematous.
follicular-based papules and pustules. Furuncles are deeper infections of the hair follicle
characterized by inflammatory nodules with pustular drainage.
Carbuncles IS GROUP OF Furuncles which can coalesce to form larger draining nodules ().
Treatment folliculitis.

6. FOLLICULITIS

7. Treatment
If systemic antibiotics are indicated, coverage should include Staphylococcus aureus since it is
the most common pathogen. Because this organism may be penicillin resistant, dicloxacillin 250
mg PO q6h for 7-10d or a cephalosporin such as cephalexin 250-500 mg q6h for 7-10d are the
initial choices of therapy.
For patients in whom S.aureus colonization is suspected, bleach baths or bleach soaks may be
beneficial
Topical treatment with: Clindamycin 1% or erythromycin 2%, applied two or three times a day
to affected areas.

8. ABSCESS
Abscess is a tender, soft, swelling filled with pus, often surrounded by an area of skin coloured
from pink to deep red.
Risk Factors: that predispose individuals to developing an abscess include: Diabetes - Obesity -
Intravenous drug abuse Weakened immune system due to underlying illness or medication

9. Abcess

10. Treatment
Surgical drainage & systemic antibiotics
Empiric therapy:
1. Clindamycin 300-450 mg PO q8h for 5-7d or.
2. Cephalexin 250-500 mg PO q6h for 5-7d or.
3. Dicloxacillin 250-500 mg PO q6h for 5-7d or.
4. Doxycycline 100 mg PO q12h for 5-7d or.
5. Trimethoprim-sulfamethoxazole (160 mg/800 mg) DS 1-2 tablets PO q12h for 5-7d

11. IMPETIGO
Impetigo is the most common bacterial infection in children. This acute, highly contagious
infection of the superficial layers of the epidermis is primarily caused by Streptococcus
pyogenes or Staphylococcus aureus.
Secondary skin infections of existing skin lesions (eg, cuts, abrasions, insect bites, chickenpox)
can also occur. Methicillin-resistant S aureus (MRSA) and gentamicin-resistant S aureus strains
have also been reported to cause impetigo.
Impetigo is classified as
1. Non-bullous (impetigo contagiosa) (about 70% of cases)
2. Bullous

12. Impetigo

13. Treatment
Treatment of impetigo typically involves local wound care along with antibiotic therapy.
Antibiotic therapy for impetigo may be with a topical agent alone or a combination of systemic
and topical agents.
Gentle cleansing, removal of the honey-colored crusts of nonbullous impetigo using
antibacterial soap and a washcloth, and frequent application of wet dressings to areas affected
by lesions are recommended.
Topical Antibiotic Treatment options: Mupirocin (Mupirocin ointment (Bactroban) has been
used for both the lesions and to clear chronic nasal carriers. But it is expensive), Retapamulin
and fusidic acid.

14. ERYSIPELAS AND CELLULITIS
Erysipelas is a superficial cutaneous infection of the skin involving
Dermal lymphatic vessels./ young children/ is a tender, well-defined, erythematous, indurated
plaque on the face or legs
Cellulitis is a deeper process that extends to the subcutis./ a warm, tender, erythematous, and
edematous plaque with ill-defined borders that expands rapidly

15. Cellulitis

16. Treatment
Erysipelas: Penicillin administered orally or intramuscularly is sufficient for most cases of classic
erysipelas and should be given for 5 days, but if the infection has not improved, treatment
duration should be extended. A first-generation cephalosporin may be used if the patient has an
allergy to penicillin.
Cellulitis:
1. In mild cases of cellulitis treated on an outpatient basis: Dicloxacillin, amoxicillin, or
cephalexin.
2. In patients who are allergic to penicillin: Clindamycin or a macrolide (clarithromycin or
azithromycin)
3. An initial dose of parenteral antibiotic with a long half-life (eg, ceftriaxone) followed by an
oral agent.

17. FUNGAL AND YEAST
INFECTIONS
DERMATOPHYTOSIS, CANDIDIASIS, AND CANDIDAL INTERTRIGO.

18. DERMATOPHYTOSIS
Dermatophytosis implies infection with fungi, organisms with high affinity for keratinized tissue,
such as the skin, nails, and hair. Trichophyton rubrum is the most common dermatophyte
worldwide. Fungal reservoirs for these organisms include soil, animals, and infected humans.it
include
1. Tinea Pedis (athlete's foot)
2. Tinea Cruris (jock itch)
3. Tinea Corporis

19. Tenia corporis

20. Tenia cruris

21. Dermatophytosis

22. Tines pedis

23. Treatment
Class of drugs Drug name Formulation and Frequency of application
Allylamines Naftifine 1% cream, Once daily
Terbinafine 1% cream or solution Once or twice daily
Benzylamine Butenafine 1% cream Once or twice daily
Imidazoles Clotrimazole 1% cream, solution, or lotion Twice daily
Econazole 1% cream Once daily
Ketoconazole 1% cream Once daily
Miconazole 1% shampoo Twice weekly
Oxiconazole 2% cream, spray, lotion, or powder Twice daily
Sulconazole 1% cream or lotion Once or twice daily
Miscellaneous Ciclopirox 1% cream or lotion Twice daily
Tolnaftate 1% cream, solution, or powder Twice daily

24. CANDIDIASIS
Candidiasis refers to a diverse group of infections caused by Candida albicans or by other
members of the genus Candida. These organisms typically infect the skin, nails, mucous
membranes, and gastrointestinal tract, but they also cause systemic disease.
Prevalence and Risk Factors Infection is common in immunocompromised patients, diabetics,
the elderly, and patients receiving antibiotics.

25. Candidiasis

26. Treatment
For candidal intertrigo and balanitis, topical antifungal agents such as clotrimazole, terbinafine,
or econazole cream, applied twice daily for 6 to 8 weeks, is usually curative when coupled with
aeration and compresses.
Systemic antifungal drugs, such as fluconazole 100 to 200 mg/day or itraconazole 100 to 200
mg/day, for 5 to 10 days may be necessary for severe or extensive disease.

27. Other types of Candidiasis
Candidal intertrigo is a specific infection of the skin folds (axillae, groin), characterized by
reddened plaques, often with satellite pustules . Paronychia is an acute or chronic infection of
the nail characterized by tender, edematous, and erythematous nail folds, often with purulent
discharge
Candidal vulvovaginitis is an acute inflammation of the perineum characterized by itchy,
reddish, scaly skin and mucosa; creamy discharge; and peripheral pustules. A single 150-mg dose
of fluconazole, coupled with aeration, is usually effective for vulvovaginitis

28. PITYRIASIS VERSICOLOR
Tinea versicolor is a common opportunistic superficial infection of the skin caused by the yeast
Malassezia furfur.
Prevalence and Risk Factors Prevalence is high in hot, humid climates. Purported risk factors
include oral contraceptive use, heredity, systemic corticosteroid use, Cushing's disease,
immunosuppression, hyperhidrosis, and malnutrition.
Signs and Symptoms: Infection produces discrete and confluent, fine scaly, well-demarcated,
hypopigmented or hyperpigmented plaques on the chest, back, arms, and neck. Pruritus is mild
or absent.

29. PITYRIASIS VERSICOLOR

30. Treatment
Treatment Selenium sulfide shampoo (2.5%) or ketoconazole shampoo is the mainstay of
treatment, applied to the affected areas and the scalp daily for 3 to 5 days, then once a month
thereafter. Alternatively, a variety of topical antifungal agents, including terbinafine,
clotrimazole, or econazole cream, applied twice daily for 6 to 8 weeks.

31. VIRAL INFECTIONS
HERPES SIMPLEX, CHICKEN POX, HERPES ZOSTER, WARTS,
MOLLUSCUM CONTAGIOSUM

32. HERPES SIMPLEX
Herpes simplex virus (HSV) infection is a painful, self-limited, often recurrent dermatitis,
characterized by small grouped vesicles on an erythematous base.
Pathophysiology and Natural History Disease follows implantation of the virus via direct contact
at mucosal surfaces or on sites of abraded skin. After primary infection, the virus travels to the
adjacent dorsal ganglia, where it remains dormant unless it is reactivated by psychological or
physical stress, illness, trauma, menses, or sunlight. Primary infection occurs most often in
children, exhibiting vesicles and erosions on reddened buccal mucosa, the palate, tongue, or lips
(acute herpetic gingivostomatitis).
It is occasionally associated with fever, malaise, myalgias, and cervical adenopathy. Primary
genital infection is an erosive dermatitis on the external genitalia that occurs about 7 to 10 days
after exposure; intact vesicles are rare

33. Herpes simplex

34. Treatment
Acyclovir remains the treatment of choice for HSV infection; newer antivirals, such as famciclovir
and valacyclovir, are also effective. For recurrent infection (more than six episodes per year),
suppressive treatment is warranted.

35. Chicken pox
Chickenpox is a very contagious disease caused by the varicella- zoster virus (VZV). It causes a
blister-like rash, itching, tiredness, and fever. The rash appears first on the stomach, back and
face and then spreads over the entire body causing between 250 and 500 itchy blisters In adult
the disease associated with complication like Myocarditis, pericarditis, orchitis, hepatitis,
ulcerative gastritis, glomerulonephritis and arthritis.

36. Chickenpox

37. Treatment
Primary varicella infection in the healthy child is a rather benign disease that requires
symptomatic therapy only. Oral acyclovir should be considered for healthy persons at increased
risk of severe varicella infections.
Adults and immunocompromised persons with chickenpox have a more complicated course than
that occurring in children, and therefore, the condition necessitates a more aggressive
pharmaco-therapeutic approach. Intravenous acyclovir therapy is recommended for patients
who are immunosuppressed or immunocompromised.
Varicella-zoster immune globulin (VariZIG) is indicated for use in highly susceptible, VZV-exposed
immunocompromised or immunosuppressed populations.

38. HERPES ZOSTER
Herpes zoster (shingles) is an acute, painful dermatomal dermatitis that affects approximately
10% to 20% of adults, often in the presence of immunosuppression.
Pathophysiology and Natural History During the course of varicella, the virus travels from the
skin and mucosal surfaces to the sensory ganglia, where it lies dormant for a patient's lifetime.
Reactivation often follows immunosuppression, emotional stress, trauma, and irradiation or
surgical manipulation of the spine, producing a dermatomal dermatitis.
Signs and Symptoms Herpes zoster is primarily a disease of adults and typically begins with pain
and paresthesia in a dermatomal or bandlike pattern followed by grouped vesicles within the
dermatome several days.

39. Herpes zooster

40. Treatment
Topical Treatments: There are a variety of topic treatments, including topical acyclovir 5%
cream, lidocaine, and capsaicin. For acute HZO, a good approach is wet-to-dry dressings with
sterile saline solution or Burow solution (a pharmacologic preparation made of 5% aluminum
acetate dissolved in water), which should be applied to the affected skin for 30-60 minutes 4-6
times daily.
Pharmacologic Therapy for Herpes Zoster: The goals of therapy are as follows:
1. To shorten the clinical course
2. To provide analgesia
3. To prevent complications

41. Continued…
Pharmacological treatment includes
1. Corticosteroids: Many practitioners have long used oral prednisone and similar medications
to reduce acute pain.
2. Agents for pain control: Primary medications for acute zoster-associated pain include the
following: Narcotic and nonnarcotic analgesics (both systemic and topical), Neuroactive
agents (eg, tricyclic antidepressants [TCAs]), Anticonvulsant agents.
3. Antiviral agents: acyclovir and its derivatives (valacyclovir, famciclovir, penciclovir, and
desciclovir, which is not available in the United States) to be safe and effective in treating
active disease and preventing PHN (Postherpetic neuralgia).

42. WARTS
Warts are common and benign epithelial growths caused by human papillomavirus (HPV).
Prevalence and Risk Factors Warts affect approximately 10% of the population. Anogenital
warts are a sexually transmitted infection, and partners can transfer the virus with high
efficiency. Immunosuppressed patients are at increased risk for developing persistent HPV
infection.

43. Viral warts

44. Treatment
Physicians may also use cryotherapy, in which the wart is exposed to liquid nitrogen for one to
four treatments, separated by one to three weeks.
Local anesthesia may be required for pain. The pharmacist can recommend salicylic acid and
several OTC home cryotherapy products when destructive therapy is contemplated.

45. MOLLUSCUM CONTAGIOSUM
Molluscum contagiosum is an infectious viral disease of the skin caused by the poxvirus.
Molluscum are smooth pink, or flesh-colored, dome-shaped, umbilicated papules with a central
keratotic plug
Prevalence and Risk Factors: The prevalence is less than 5% in the United States. Infection is
common in children, especially those with atopic dermatitis, sexually active adults, and patients
with human immunodeficiency virus (HIV) infection. Transmission can occur via direct skin or
mucous membrane contact, or via fomites.

46. MOLLUSCUM CONTAGIOSUM

47. Treatment
Treatment might not be necessary because the disease often resolves spontaneously in children.
Treatment cryosurgery and curettage are perhaps the easiest and most definitive approaches

48. PARASITES INFECTIONS
SCABIES, HEAD LICE

49. SCABIES
Scabies is a skin infestation caused by a mite known as the Sarcoptes scabiei. Untreated, these
microscopic mites can live on your skin for months. They reproduce on the surface of your skin
and then burrow into it to lay eggs. This causes an itchy, red rash to form on your skin.
Symptoms: Itch; Rash

50. Scabies

51. Treatment
Scabies treatment includes administration of a scabicidal agent (eg, permethrin, lindane, or
ivermectin), as well as an appropriate antimicrobial agent if a secondary infection has developed.
Permethrin, oral ivermectin, and synergized pyrethrins were deemed most effective for cure and
symptomatic relief.
Treatment failures are uncommon but do occur. The most common causes of treatment failure
include the following:
1. Improper application
2. Inadequate application
3. Reinfestation - Recurrence of the eruption usually means reinfection has occurred, underscoring
the importance of treating all members of the household
4. Resistance - Resistance to lindane has been widely reported; less frequently, cases of resistance to
permethrin have been noted; resistance to ivermectin is still rare but has been reported in
patients who received multiple doses of the drug over several years.

52. HEAD LICE
The head lice is an obligate ectoparasite of humans. Head lice are wingless insects that spend
their entire lives on the human scalp and feeding exclusively on human blood
Prevalence: an estimated 6 million to 12 million infestations occur each year in the United States
among children 3 to 11 years of age.

53. Head lice

54. Treatment
Over-the-counter Medications: Pyrethrins
Prescription Medications: Benzyl alcohol 5% lotion, Malathion 5% lotion.