than the FLAABS. Although the results of these tests are diverse, they show that infection with M.leprae is far more common than it is generally accepted: From 5% to 50% of contacts. A positive ELISA is present in 95% of cases 1 or 2 years before the development of clinical signs. There is good evidence that a high proportion of early clinical leprosy (up to 12%) will resolve spontaneously. Infection Minority susceptible to leprosy disease (5%) Majority will not develop disease Indeterminate Good resistance: No bacilli No resistance: Numerous bacilli Skin-Nerve: Tuberculoid Borderline Skin-Nerve-All organs: Lepromatous Indeterminate type The indeterminate type is the earliest state of the disease. It consists of a single hypopigmented or erythematous skin lesion which may or may not be insensitive. A skin smear is usually found to be negative. The indeterminate type may heal spontaneously, remain indefinitely at this stage or progress into one of the other types. To confirm a diagnosis of indeterminate leprosy there must be impairment of sensibility (thermal sensibility gets impaired before tactile sensibility). Biopsies are useful to support th clinical diagnosis. Tuberculoid type In the tuberculoid type there are few (1 to 3) skin lesions; these are large (3 to 30 cm) macules. The lesions are hypopigmented or erythematous. They have a well defined border and are rough and scaly. The periphery is raised and erythematous or hyperpigmented; the center is flat and hypopigmented. Anesthesia or hyperesthesia is a major characteristic of these lesions. The sensation of temperature, light touch and pain are impaired in that order. Deep sensation is intact and deep tendon reflexes are normal. Loss of the ability to perspire is an important sign. Peripheral nerve involvement is common. The main nerves involved are the ones in the periphery of the lesions, the ulnar above the elbow, the median at the wrist, the common peroneal at the knee, the posterior tibial at the ankle, the radial at the elbow, the greater auricular in the neck, the sural at the lateral aspect of the ankle, and the superficial branches of the V and VII cranial nerves. Although tuberculoid Leprosy is a relatively benign disease, severe disabilities may develop. Louisiana Office of Public Health – Infectious Disease Epidemiology Section Page 3 of 12 Lepromatous type The skin lesions are very numerous small macules. They appear copper colored or erythematous. Their margin is vague and they tend to coalesce. They are symmetrically distributed over the body. They are not necessarily anesthetic. There is a generalized infiltration of the skin, often noticed by palpation rather than by visual inspection. Nodules and papules which are characteristic of lepromatous Leprosy are usually numerous. A common site for the development of nodules are the earlobes. Loss of eyebrows (starting with lateral brows) and loss of eye lashes (madarosis) are a common late signs. Alopecia of the scalp is rare. As the disease progresses, most organs may become involved: Nasal congestion, epistaxis, laryngeal inflammation, eye lesions, renal involvement, testicular atrophy and secondary gynecomastia. Nerve involvement has a slow onset and becomes more generalized to eventually affect all nerves. Borderline Type Or Dimorphous Type Clinically and histologically borderline Leprosy has features of both the lepromatous and tuberculoid types. The majority of leprosy cases are borderline, but for particular purposes, they are often classified as Tuberculoid or Lepromatous (T or L). The word dimorphous is sometimes used instead of borderline. Skin lesions are a mixture of T or L lesions, with a tendency to be more erythematous. The disease is unstable and may progress towards a more polar form (T or L). Paucibacillary-Multibacillary Cases Paucibacillary cases are the smear negative I and T cases of Madrid classification (I, TT and BT of Ridley Jopling classification) with a BI=0 at all sites. Multibacillary cases are L and B cases of Madrid classification (LL, BL, BB and BT of Ridley Jopling classification) with a BI>0. In previous definition, paucibacillary had a BI of 0 or 1 but this was reduced in the latest definitions because of the poor results