Clinical presentation

Tuberculoid leprosy affects the nerves and the skin. Nerves may be thickened, and anaesthesia or muscle atrophy is found. Skin lesions often occur on the face, and as few as one or two may be seen. They usually take the form of raised red plaques with a hypopigmented centre, which is typically dry and hairless (Fig. 1). Sensation may be impaired within the plaque.

Fig. 1 Hypopigmented plaques of tuberculoid leprosy.

The skin lesions of lepromatous leprosy are multiple and take the form of macules, papules, nodules and plaques. They are symmetrical and tend to involve the face, arms, legs and buttocks. Sensation is not impaired. Untreated, the condition is infectious from the nasal involvement. Progression gives a thickened furrowed appearance to the face (leonine facies) with loss of eyebrows (Fig. 2). Borderline leprosy shows features intermediate between lepromatous and tuberculoid.

Fig. 2 The leonine facies of lepromatous leprosy.

Leprosy must be distinguished from a variety of other dermatological conditions (Table 1).

Table 1 Differential diagnosis of leprosy

Complications

Tuberculoid leprosy may result in bone damage to a hand or foot from repeated trauma to an insensitive area. In lepromatous leprosy, nasal damage may progress to a saddle nose defect. Ichthyosis, testicular atrophy and leg ulcers are seen. A peripheral neuropathy leads to shortening of the toes and fingers from repeated trauma. Lepra reactions, which result from an upgrading or a downgrading of the immune response, can produce nerve destruction or acute skin lesions.

Management

Lepromatous (multibacillary) leprosy is treated with rifampicin, dapsone and clofazimine. Treatment is for at least 2 years, continued until skin smears are negative. Tuberculoid (paucibacillary) leprosy responds to rifampicin and dapso ne, given for 6 months. The complications of leprosy may require the skills of rehabilitation specialists and orthopaedic and plastic surgeons.

In countries where leprosy is endemic, the education of the public about the disease is important in reducing the stigma attached to sufferers. Public health programmes aimed at leprosy control are active in several countries.

Clinical presentation

Oriental sore is a common infection in endemic areas normally affecting children, who subsequently develop immunity. In non-endemic regions, it is not infrequently seen in travellers after a Mediterranean holiday. The face, neck or arms are usually affected. At the site of inoculation, a red or brown nodule appears, which either ulcerates or spreads slowly to form a crust-topped plaque (Fig. 3). Untreated, the lesion will heal in 6–12 months, although a chronic form is seen. In mucocutaneous leishmaniasis, the skin lesion resembles an oriental sore but, subsequently, necrotic ulcers affect the nose, lips and palate with deformity. Kala-azar principally affects children and has a significant mortality. It causes hepatomegaly, splenomegaly, anaemia and debility. The cutaneous signs are patchy pigmentation on the face, hands and abdomen.

Fig. 3 The oriental sore of cutaneous leishmaniasis.

Small lesions may respond to cryotherapy. Otherwise, intravenous sodium stibogluconate may be given.

Leishmaniasis must be distinguished from some other disorders (Table 2).

Table 2 Differential diagnosis of leishmaniasis

Management

Cutaneous leishmaniasis may heal spontaneously, and small areas respond to cryotherapy. When specific treatment is needed, it is usual to give sodium stibogluconate (Pentostam) intravenously, usually for 15–21 days. The treatment for the mucocutaneous and visceral forms is similar.