Infections and infestations are by far the most frequent forms of skin pathology in tropical countries. As well as treating affected individuals, it is important to consider these conditions as indicators of the general standard of hygiene and sanitation and to define appropriate public health interventions (provision of water that is adequate in quality and quantity, health education, soap...).
Clinical assessment of the patient
The physical examination:
- Describe the basic lesions:
· weeping lesions
- Look for pruritis.
- Look for regional or systemic manifestations: lymphangitis, adenopathy, fever, septicemia, metastatic infection...
- Look for a cause: mosquito bite, jewelry, allergy, scabies, lice, otitis media.
- Consider the nutritional status and the general health of the family, particularly for infectious dermatosis.
Patients with dermatological conditions often present late. At
this stage, initial and specific signs are often replaced by infection. In these
cases, treating the overlying infection is not enough.
Patients should be re-examined after the treatment of infection.
Highly contagious skin infection (streptococcal or staphylococcal affecting mainly children of school age).
-Initially lesions located around orifices.
- Multiple crusty lesions, sometimes associated with pustules (one to several). Lesions are extended by scratching
- Acute impetigo produces bullous lesions.
- Streptococcal lesions are superficial, staphylococcal lesions are deep.
- Cut fingernails, instruct mother to wash child daily with soap.
- Clean lesions with a disinfectant (chloramine or chlorhexidine-cetrimide solution; preparation: see table 25). Remove crusts, incise any abscesses.
- Apply gentian violet solution twice daily.
- On the scalp look for head lice or ringworm (tinea capitis).
- Explain treatment to the mother and treat other members of the family as necessary.
- Do not give antibiotics unless there are signs of regional or systemic spread. If so:
Adult: 2.4 MIU/d divided in 3 doses x 5 days
Child: 100,000 mg/kg/d divided in 3 doses x 5 days
If no improvement or extensive abscesses, staphylococcal
infection is likely. If available give: erythromycin (PO): 50 mg/kg/d divided in
3 doses x 5 days
cloxacillin(PO): 100 mg/mg/d divided in 3 doses x 5-7 days
- Carbuncles on the face. There is a danger of intracerebral
metastasis, so treat vigorously for 5-7 days.
cloxacillin (IV or PO): 100 mg/kg/d divided in 4 injections x 7 days
chloramphenicol(IV): 75 mg/kg/d divided in 4 injections x 7 days
ampicillin (IV): 100 mg/kg/d divided in 4 injections x 7 days
+gentamicin (IM): 3 mg/kg/d divided in 2 or 3 injections x 7 days
Relapsing vesicular eruption due to Herpes simplex virus affecting the mucus membranes and skin. Facial infections may be serious if they involve the eye.
- Clean the lesions with an antiseptic such as chlorhexidine-cetrimide solution (dilution: see table 25).
- If affecting buccal mucosa then treat as for stomatitis.
- If affecting the face encourage ocular hygiene.
- If generalized bacterial super infection, treat as for staphylococcal impetigo.
Acute dermatosis due to resurgence of the varicella-zoster virus, which also causes chickenpox. Preceded by severe neuralgic pain, the eruption is vesicular on an erythematous base and is almost invariably unilateral, occupying the dermatome of a peripheral nerve.
As above, plus analgesia.
Contagious skin infestation caused by a mite, Sarcoptes scabiei. Its occurrence is closely related to a lack of water and poor hygiene.
- Nocturnal itching, scratch marks, burrows between the
(made visible by applying ink, then washing it off), and papules.
- Secondary infection (from scratching) resembles impetigo.
- Whole family is often infested.
- Often localised to: genital region, axillae, chest, breasts, hands and thighs.
- Wash the whole body with a mild soap and dry, then apply 25 % benzyl benzoate emulsion (BBE) to the whole body except head and neck. Use a broad paint brush if available. Allow to dry, then put on the same clothes.
- Repeat for 3 days.
- If a secondary bacterial infection occurs, treat as for impetigo for 4 to 5 days. Only apply benzyl benzoate emulsion once all lesions are closed (is very irritant).
- Treat the whole family. After the treatment, boil and air all clothes and bedding.
- Warn patients that itching may persist for several weeks. This represents an allergic reaction to the dead mites, not treatment failure.
Erosive lesion of the skin, usually occurring on the lower leg caused by:
- vascular (venous and/or arterial) insufficiency,
- bacterial or parasitic infection,
- underlying metabolic disorders.
Phadegenic ulcers have no apparent cause, they extend and become chronic.
- Clean with chlorhexidine-cetrimide or chloramin solutions (dilution: see table 25).
- Excise necrotic edges.
- Daily dressing.
- Rest with leg elevated.
- Give oral antibiotics if local treatment fails:
Adult: 2.4 MIU/d divided in 3 doses x 5 days
Child: 100,000 IU/kg/d divided in 3 doses x 5 days
If no improvement, give:
erythromicin (PO): 50 mg/kg/d divided in 3 doses x 7 days
- Skin graft if ulcer is large. Only graft after local treatment has rendered it clean and flat with red granulation tissue in the base.
- Think of Guinea worm in endemic zones.
- Give tetanus toxoid.
Erythema of the buttocks and perineum, sometimes "weeping". Caused by infection with Candida albicans.
- Clean with usual soap or an antiseptic (chloramine or chlorhexidine-cetrimide; preparation: see table 25).
- Apply gentian violet solution twice daily.
- Avoid damp clothing (leave buttocks bare).
- Intestinal thrush often co-exists:
Nystatin (PO): 4-600,000 IU/d divided in 3 doses x 10 days (vaginal tabs might be used for this purpose)
Highly contagious fungal infections. Prevalence is associated with the level of personal hygiene.
There are several different forms:
- Pityriasis versicolor with depigmented patches.
- Erythematous lesions in the skin folds (e.g. axillae and groin).
Associated with loss of hair. Highly contagious in families.
- Wash, dry and then apply whitfield's ointment twice a day.
- Use griseofulvin only in extensive cases (see below).
- Cut hair and then shave the head.
- Wash, dry and then apply gentian violet twice a day for several weeks.
- If treatment fails use:
Adult: 500 mg to 1 g/d divided in 3 doses
Child: 10 mg/kg/d divided in 3 doses
Treat for 10 days (sometimes treatment has to be continued for 1 month).
- Examine all the family.
- A short course of griseofulvin may be effective for adults:
griseofulvin: 1.5 g taken at the same time as a greasy meal.
However, there is a risk of digestive problems and vertigo.
A bacterial zoonosis of herbivorous mammals that is transmitted to humans by skin contact with carcasses or animal products, and rarely by ingestion of undercooked infected meat.
- Pustule that develops into a black eschar surrounded by vesicles and an inflamed area, with regional adenopathy. Painless.
- May cause fatal septicemia.
- Intestinal and pulmonary forms exist.
penicillin: PPF(or procain penicilline) IM
Adult: 4 MU / d in a single injection x 5 days
Child: 100,000 U/kg/d in a single injection x 5 days
Adult: 4 MU/d divided in 3 doses x 7 days
Child: 100,000 U/kg/d divided in 3 doses x 7 days
chloramphenicol per os
Adult: 1.5-2 g/ d divided in 3 doses x 7 days
Child: 75 mg/kg/d divided in 3 doses x 7 days
tetracycline per os
Adult: 1.5-2 g/d divided in 3-4 doses x 7 days
Child > 8 years: 50 mg/kg/d divided in 3-4 doses x 7 days
Look for the source of contamination and take measures to prevent further transmission.
- Erythema with crusting, scaling, itching, and desquamation.
- Look for a cause (e.g. irritants, allergic, fungal, family history).
- Apply gentian violet solution. If infected, treat as for impetigo.
- If chronic, consider an eczematized scabies infestation and treat appro-priately.
- Rapidly developing itchy papules.
- Look for a cause (e.g. insect bites, drug allergy, invasive stage of a parasitic infection of ascaris, hookworm, strongyloides, schisto-somiasis or loa-loa).
- Intense itching:
promethazine (PO): 75 mg/d divided in 3 doses x 5
chlorphenamine (PO): 12 mg/d divided in 3 doses
- Angiedema (laryngeal or pharyngeal
dexamethasone (IV): 4 mg (repeat if necessary)
- If anaphylactic shock, see "Shock".
- Multiple lesions: desquamation, bullas...
- To prevent secondary infection, clean lesions with either chloramine or chlorhexidine-cetrimide solution and apply gentian violet (see table 25).
Dermatosis affecting sun-exposed skin due to a dietary deficiency in niacin and/or tryptophane. Commonest in populations whose staple carbohydrate is maize.
- Classically, "three D's": dermatitis, diarrhea and dementia.
- The dermatitis is painful, more marked in sun-exposed areas of forehead, neck, forearms and legs... symmetrical.
- Diarrhoea and neurological symptoms indicating serious
nicotamide (vitomin PP)
Adult: 300 mg/d
Child: 300 mg/d until healing is complete and in conjunction with a rich protein diet.
If unavailable, use:
Adult: 6 caps/d divided in 3 doses x 15 days
Child: 3 caps/d divided in 3 doses x 15 days
Provide nutritional education (e.g. diversify staples, advise vegetables such as beans and lentils).
Leprosy may in some instances resemble a chronic dermatosis such as eczema or pityriasis versicolor. Whenever there is the slightest doubt, perform a full examination of the peripheral nerves and take specimens for microscopy.
Non-venereal treponematoses, affecting bone, skin or mucosa and spread by direct contact. Their occurrence is associated with over crowding and poor hygiene.
- benzathine penicillin (IM)
Adult: 1.2 MIU in a single injection
Child: 600,000 IU in a single injection
- Note that syphilis (both primary and secondary) must be treated with double this dose of benzathine penicillin: 2.4 MIU IM stat.
- If allergic to penicillin: tetracycline or erythromycin (PO): 2 g/d or 50 mg/kg/d divided in 3 doses x 5 days (14 days for syphilis)
For all household contacts:
benzathine penicillin (IM)
Adult: 600,000 IU in a single injection
Child: 300,000 IU in a single injection
A chronic infectious disease caused by the Hansen bacillus
(Mycobacterium leprae) and affecting the skin, mucosae and peripheral
Humans are the only significant reservoir of infection.
COMPLETE CLINICAL EXAMINATION
- Patient must be undressed.
- The entire skin surface must be examined.
- Note the appearance of any lesions.
- Test the sensation (fine touch and pin-prick) of the lesions.
- Palpate the main peripheral nerves to detect any hypertrophy.
- Examine peripheral nervous function: motor, sensory and proprioception.
- Examine the nasal mucosa to detect any chronic rhinitis.
- Scraped incision method to obtain tissue juice but no
Pinch a fold of skin with a Kocher forceps so as to make it bloodless, incise and saape the scalpel blade along the inside of the incision.
· one specimen from the edge of a lesion.
· one from the earlobe.
- Also take a nasal swab.
CLASSIFICATION (RIDLEY-JOPLING SYSTEM) (See table D)
Principles of management
The increasing frequency of strains of M. leprae resistant to dapsone poses a serious threat to leprosy control programs. The strategy of multiple drug therapy must be instituted in order to combat this problem.
It is patients with multibacillary forms of leprosy (BL and LL) who are most exposed to the risk of drug resistance and who are also most infectious to their household contacts.
The treatment of lepromatous leprosy has three objectives:
1. to reduce transmission
2. to cure the patient
3. to prevent the emergence of resistant strains of M. leprae
Patients with tuberculoid leprosy are less infectious but are more likely to suffer paralysis of peripheral nerves. The main objective of their treatment is to preserve function.
Patients under therapy are exposed to the risk of developing severe reactions. For this reason, as well as to ensure compliance, supervision is necessary. The program must be well planned, organized and adequately staffed.
"Partially supervised" regimens work best. Daily doses of dapsone can be taken at home by the patient, but monthly doses of rifampicin should be administered by a health worker. The worker must ensure that the patient swallows the medication.
LEPROMATOUS LEPROSY (dispensary)
rifampicin (PO): 600 mg once per month, supervised
dapsone (PO): 100 mg daily, at home
clofazimine (PO): 300 mg once per month, supervised and 50 mg daily, at home
Duration of therapy: 2 years or more, depending upon progress
TUBERCULOID LEPROSY (dispensary - hospital)
rifampicin (PO): 600 mg once per month, during 6 months
dapsone (PO): 100 mg daily during 6 months (1-2 mg/kg/day)
- rifampicin must always be taken under supervision.
- dapsone may be taken at home. If treatment is interrupted, a full 6 months regimen should be completed after the medication has been discontinued.
- Either reversal reactions (upgrading: shift towards TT end of spectrum) or erythema nodosum leprosum (ENL).
- Treat with clofazimine(PO): 100 to 300 mg/d
- If severe, use corticosteroids:
prednisone (or prednisolone) PO: 80 mg D1; 75 mg D2; 70 mg D3; 65 mg D4; 60 mg D5...then decrease 5 mg every day.