Impetigo Causes and Treatment
Most cases of impetigo and cellulitis are attributed to S. aureus and GABHS alone or in combination (Table 2) (19). A retrospective study investigated both the aerobic and anaerobic Impetigo and cellulitis, diabetic, and chronic skin ulcers Streptococcus group A Staphylococcus aureus microbiology of nonbullous impetigo in 40 children (20). Aerobic or facultative anaerobic bacteria only were present in 24 patients (60 ), strict anaerobic bacteria only in 5 patients (12.5 ), and mixed anaerobic-aerobic flora was present in 11 patients (27.5 ). Sixty-four isolates were recovered 43 aerobic or facultative and 21 anaerobic. The predominant aerobic and facultative bacteria were S. aureus (29 isolates) and GABHS (13). The predominant anaerobes were Peptostreptococcus spp. (12), pigmented Prevotella spp. (5), and Fusobacterium spp. (2). Single bacterial isolates were recovered in 17 patients (42.5 ), 13 of which were S. aureus. S. aureus alone or mixed with GABHS or Peptostreptococcus spp....
Streptococcal impetigo manifests itself as appearance of small vesicles that rapidly pustulate and rupture. After the purulent discharge dries, a golden-yellow crust forms. The lesions remain superficial and do not ulcerate or infiltrate the dermis. Pain and scarring do not occur. The bullous form of impetigo is due to Staphylococcus aureus (phage group II, usually type 71). The initial vesicles turn into fluid bullae that quickly rupture, leaving a moist red surface, which then generates varnish-like light brown crusts. Nikolsky sign and scarring do not occur.
The dorsal aspect of the distal phalanx may be involved by impetigo (Figure 5.39). It presents in two forms The latter is characterized by the appearance of large, localized, intra-epidermal bullae that persist for longer periods than the transient vesicles of streptococcal impetigo which subsequently rupture spontaneously to form very thin crusts. The lesions of bullous impetigo may mimic the non-infectious bullous diseases (such as drug-induced types or pemphigoid). Oral therapy of bullous impetigo with a penicillinase-resistant penicillin should be instituted and continued until the lesions resolve. Cephalexin and erythromycin are acceptable alternatives. The lesions should be cleansed several times daily and topical aureomycin (3 ) applied to all the affected areas. Impetigo of the nail apparatus. Impetigo of the nail apparatus.
Bullous impetigo (pemphigus neonatorum) in a newborn infant at the age of 6 days. This infection may occur as early as the second day or as late as two weeks of life and may demonstrate bodi bullous and impetiginous lesions. It is most commonly due to a staphylococcal infection but, on occasion, is caused by Streptococcus. The lesions are more common in moist, warm areas such as the axillary folds of the neck or the groin and present as superficial bullae which are wrinkled, become flaccid, and rupture easily producing ulcers which become crusted. Note the impetigo of the umbilical area.
Blistering distal dactylitis is a variant of streptococcal skin infection. It presents as a superficial, tender, blistering beta-haemolytic streptococcal infection over the anterior fat pad of the distal phalanx of the finger (Figure 5.40). The lesion may or may not have a paronychial extension. This blister, containing thin, white pus, has a predilection for the tip of the digit and extends to the subungual area of the free edge of the nail plate. The area may provide a nidus for the beta-haemolytic streptococcus and act as a focus of chronic infection similar to the nasopharynx. The age range of affected patients is 2-16 years. For local care incision, drainage and antiseptic soaking are indicated, giving a more rapid response than systemic antibiotic therapy alone effective regimens include benzylpenicillin (penicillin G) in a single intramuscular dose, a 10-day course of oral phenoxymethylpenicillin or eryhromycin ethyl succinate. This type of treatment decreases the reservoir of...
Syphilitic pemphigus showing the large vesiculobullous hemorrhagic lesions on the soles of both feet. These lesions are relatively rare but, especially when seen on the palms and soles, are highly diagnostic of this disease. The lesions may contain a cloudy hemorrhagic fluid that teems with organisms and is highly contagious. With bullous lesions such as these, other dermatologic diagnoses should be excluded (bullous impetigo, epidermolysis bullosa, congenital bullous ichthyosiform erydiroderma, etc.).
Infectious CL can be either acute unilateral or bilateral, and chronic (subacute). Because of the high frequency of CL in children, most microbiological studies were done in this age group. The most common causes of bilateral CL in children are viruses. However, the adenitis appears and resolves quickly without treatment. The most common viruses are EB, cytomegalovirus, herpes simplex, adeno virus, enterovirus, roseola, and rubella. Other pathogens include Mycoplasma pneumoniae and Corynobacterium diphtheria. The most common bacterial organisms causing acute unilateral infection associated with facial trauma or impetigo are S. aureus and GABHS (66-70). Other rare aerobic pathogens are S. pneumoniae and gram-negative rods. Other causes include Bartonella henselae, Francisella tularensis, Pasteurella multocida, Yersinia pestis, Actinoba-cillus actinomycetemcomitans, Burkholderia gladioli, M. tuberculosis, and non-TB Mycobacterium spp. (71-73). The presence of dental or periodontal...
Goatpox virus (GTPV) A species in the genus Capripoxvirus. Clinically causes a disease similar to sheeppox, but the disease in goats takes a milder course. Causes focal epidermal lesions which proceed through papule, vesicle and pustule stages to scab formation. Lesions are usually on the udder, teats, scrotum, inside of the thighs and less frequently around the eyes and mouth, whereas in contagious ecthyma, the lips and mouth are primarily involved. Antigenically distinct from contagious ecthyma virus and there is no cross-protection. Replicates on the CAM producing opaque pocks and in cell cultures of lamb and kid kidney tissue with CPE. Transmissible to sheep and allegedly to calves and rabbits. Experimental vaccines have been used which protect both sheep and goats against capripoxvirus infection, but a commercial vaccine is not presently available. Occurs in many parts of the world.
Pemphigus, bullous impetigo, and the staphylococcal scalded-skin syndrome. N Engl J Med 2006 355 1800-10. 19. Dagan R, Bar-David Y. Double-blind study comparing erythromycin and mupirocin for treatment of impetigo in children implications of a high prevalence of erythromycin-resistant Staphylococcus aureus strains. Antimicrob Agents Chemother 1992 36 287-90. 20. Brook I, Frazier EH, Yeager JK. Microbiology of nonbulbous impetigo. Pediatr Dermatol 1997 14 192-5. 37. Ferrieri P, Dajani AS, Wannamaker LW, et al. Natural history of impetigo. I. Site sequence of acquisition and familial patterns of spread of cutaneous streptococci. J Clin Invest 1972 51 2851-62. 38. Dillon HC. Impetigo contagiosa suppurative and non-suppurative complications. I. Clinical bacteriologic, and epidemiologic characteristics of impetigo. Am J Dis Child 1968 115 530-41.
Other forms of local bacterial infection include impetigo, folliculitis, and furuncles (boils). These conditions are caused by Staphylococcus aureus and in the case of folliculitis or boils the infection is associated with a local abscess. Staph. aureus colonises the anterior nares or perineum of normal people it also commonly colonises eczema and may cause an acute exacerbation of atopic dermatitis. Impetigo is a superficial infection of the skin of which there are two forms. In the non-bullous form the affected skin is covered with crusts. Both staphylococci and streptococci are responsible. However the bullous form which presents with blisters is due to staphylococci. Folliculitis, an inflammation of the hair follicle, is commonly caused by Staph. aureus. Infection of the scalp or beard hair (sycosis barbae) is uncommon but may become chronic. Abscess formation around the hair follicles may result in furuncles or boils where several furuncles coalesce the lesion is known as a...
The proximal nail fold, with its distal cuticle attached to the nail and the ventral eponychium, is normally well adapted to prevent infections and external inflammatory agents entering the proximal matrix area the same is true of the lateral nail walls and folds. It is therefore probable that no paronychia is truly primary, there always being some physical or chemical damage preceding the infection or inflammation this is less true in relation to superficial infections on the dorsum of the proximal nail fold, such as 'bulla repens' (a bullous form of impetigo).
Skin disease is extemely common in the tropics, affecting up to 50 of the population. Most are infections or infestations such as impetigo, ringworm, and scabies. These can easily be treated but continue to be common because of overcrowding, poverty, and the lack of resources given to health care (training of health personnel and lack of basic medicines). To a large extent such diseases can be controlled with very simple measure suitable for use by those with minimal training. Atopic eczema is just as common in urban areas in the tropics as in the west. Skin cancers are uncommon in those with a black skin because of the protective effect of melanin, but are common in albinos.
This is a lesion of bullous mastocytosis (urticaria pigmentosa) that presented at birth in this infant as a solitary bullous lesion on the sole of the right foot. Note the area of redness surrounding the lesion (dermatographism) following examination of the lesion. Spontaneous remission of the skin lesions usually occurs. It is rare for lesions to appear after the age of 3 years. Differential diagnosis includes bullous impetigo, epidermolysis bullosa, incontinentia pigmenti, and bullous congenital ichthyosiform erythroderma.
Amagai M, Matsuyoshi N, Wang ZH, Andl C, Stanley JR (2000b) Toxin in bullous impetigo and staphylococcal scalded skin syndrome targets desmoglein 1. Nature Med 6 1275-1277 blister formation in pemphigus or impetigo J Invest Dermatol 122 A33 Nousari HC, Anhalt GJ (1999) Pemphigus and bullous pemphigoid. Lancet 354 667-672 Ochsendorf FR, Schofer H, Milbradt R (1987) Pemphigus erythematosus - detection of
Other common dermatoses that respond to antifungal creams (for example Clotrimazole) include tinea cruris and pedis and candidiasis. Folliculitis often responds to 1 hydrocortisone and antifungal cream, impetigo to antibiotics and shingles to aciclovir, valaciclovir or famciclovir. Recurrent perianal or genital herpes may become more troublesome, with recurrences lasting longer and occurring more frequently if this persists for more than 3 months it is considered an AIDS-defining opportunistic infection (Group IVC1). Treatment with long-term acyclovir, valaciclovir or famciclovir suppression is often required. Genital and perianal warts are common, difficult to treat and frequently recurrent, and high-grade cervical dysplasia is seen more often in HIV-infected women.