Clinical Signs and Symptoms


            Despite the images of deformed faces and crooked hands, the early stages of leprosy can be remarkably hard to identify. Most times, the patient with leprosy will initially discover that they numb in one part of their body—after, say, a burn with a cigarette that resulted in no pain along with patches of skin that are not itchy or painful (Pfaltzgraff 135). Indeed, it is only until further investigation is it discovered the extent on the anesthesia, along with skin lesions.




            Despite anesthetic lesions being a common sign of leprosy, pain can exist. The patient may report paresthesia (a feeling of pins and needles), severe pain upon trauma of an affected limb, or pain that shoots from the face, trunk or appendages into other parts of the body (Pfaltzgraff 136).




            Lesions that occur in the body, such as macules (skin blemishes) or plaques (scaly patches), will demonstrate anesthesia when it is touched (Pfaltzgraff 136). Some clinicians recommend using a filament to test areas specifically, while others, particularly in more austere locations, simply recommend the use of a feather. Other symptoms, including that of hypopigmentation (lighter skin color), hair loss and different textures can also be remarkable features in these lesions. However, the visual identification of such lesions are commonly confused with other skin problems such as dermatitis (skin allergies), ringworm infection (tinea corporis), leishmaniasis, syphilis or psoriasis; the key feature in leprosy associated lesions is anesthesia in the center of these patches.


 Above Right : A paucibacillary (tuberculoid) lesion; if touched, no sensation is noticed

Photo Credit: Atlas of Leprosy, Revised Edition. Ricardo Guinto, et al. 1983



Left : Although such a presentation in the past would be described as borderline tuberculoid leprosy, the patient on the left would be diagnosed by WHO standards today as having multibacillary leprosy due to the high number (>5) of lesions.  The patches are scaly and partially anesthetic.

Photo Credit: Atlas of Leprosy, Revised Edition. Ricardo Guinto, et al. 1983



            The lesions appear to favor areas that are cooler than the body temperature; as such, areas close to the skin, superficial nerves (see below), eyes and nose are areas which lesions are frequently noted.


Left: In this infrared image, areas that are cooler can be identified (such as the nose and ears). These areas correspond to locations where leprosy lesions are most commonly found.

Photo Credit:








Right : A multibacillary leprosy patient; notice the loss of eyebrows and the nodules in the eyebrows, cheek, nose and ears, corresponding to cooler locations of the face.

Photo Credit: Atlas of Leprosy, Revised Edition. Ricardo Guinto, et al. 1983





Peripheral nerve enlargement



Above: The enlargement of certain nerves (left to right: great auricular nerve, supraoribital nerve and radial cutaneous nerve) is a hallmark sign of leprosy.

Photo Credit: Roy Pfaltzgraff, Clinical Leprosy, Leprosy. 1985



            The enlargement of certain nerves is unique to leprosy, as few other diseases demonstrate this sign. When the leprosy bacteria replicates within Schwann cells, which insulates nerves to protect signal transduction, the resulting enlargement is a key way to identify leprosy, particularly in areas lacking extensive laboratory techniques (Gladwin 107).  Areas that are particularly common include the ulnar or median nerve (located in the arm), posterior tibial nerve (in the foot) and those in the neck and face. The damage resulting from the multiplication of bacteria can result in other noteable signs, such as “clawing” of the hands or foot, an inability to close eyes, or atrophy (loss) of the thenar (palm) muscle and difficulty opposing the thumb. Anesthesia of the limb can result in inadvertent trauma; the resulting infection can cause severe deformities and loss of the limb, and is one of the more dramatic presentation of leprosy.


Differences between PB and MB leprosy


          In the past, there has been a multitude of ways to determine the severity of leprosy. However, in an effort to simplify treatment, the World Health Organization has categorized the disease into two different classes: paucibacillary (PB) leprosy and multibacillary (MB) leprosy (WHO). The following are key differences:



Paucibacillary (PB)

Multibacillary (MB)


Previously called

Tuberculoid Leprosy

Lepromatous Leprosy



Can be extreme

(Without treatment, the patient will die)

Unique Signs and Symptoms

Significantly milder with skin lesions and peripheral nerve enlargement as the only usual signs, possibility of spontaneous recovery

Lion-like face due to inflammation (leonine facies), as well as nasal cartilage damage causing saddle-nose deformity, blindness due to scarring of the eye can result, infertility may result in men

Distribution of lesions




Occurs When

Infected person is able to mount a robust, cell-mediated immune response to the bacterium

Infected person unable to mount a cell-mediated immune response to the bacterium

Defined by World Health Organization as

1-5 patches associated with leprosy

>5 patches associated with leprosy

Is the person Infectious?


Possibly; bacterium is found in high concentrations in respiratory secretions and organs, but it is not clear how it is spread to another person

Prospects for Recovery


Cure from disease possible, however, underlying disease complications (such as limb damage due to infection) may not be reversible or require reconstructive surgery



Above: The boy on the left has paucibacillary leprosy; the plaque on his cheek is completely insensitive.  The boy on the right has multibacillary leprosy, as identified by his “leonine” like features, the loss of eyebrows and nodules on his face. The swollen digits are characteristic of infiltration.

Photo Credit: Atlas of Leprosy, Revised Edition. Ricardo Guinto, et al. 1983




Above: Additional drawings of 19th century leprosy patients. From left, the man demonstrates facial paralysis, demonstrative of facial nerve involvement. The woman in the center not only has nodules, but also loss of eyebrows and what appears to be scarring of the right eye. The rightmost  woman, who at the time is said to be 28 years old, has extensive, disfiguring nodular leprosy; all three have multibacillary leprosy.

Photo Credit: Peter Richards, The Medieval Leper, 2000



Above: An inability to close the eye due to leprosy, lack of lubricating tear and exposure to the elements has resulted in keratopathy. Blindness in such cases will result.

Photo Credit: Margaret Brand. Eye complications in leprosy, Leprosy. 1985


Under the microscope


            There are also unique differences microscopically between pauncibacillary leprosy and multinacillary leprosy. During microscopic examination, a specific stain for acid-fast bacilli helps identify the bacteria; this can be particularly difficult to the untrained eye and thus requires significant training before such a technique is used to verify infection.




Above: On the left side is microscopic image of a nerve cell with a lone acid-fast bacillus; a Fite-Faraco stain has been used to identify the acid-fast bacteria. The patient has paucibacillary leprosy. On the right side is another patient with numerous acid-fast bacilli within the nerve; this patient has multibacillary leprosy. 

Photo Credit: Atlas of Leprosy, Revised Edition. Ricardo Guinto, et al. 1983