Department of Pediatrics
University of Wisconsin School of Medicine and Public Health

Tutorial B: The Secondary Lesions

Secondary lesions may evolve from primary lesions, or may be caused by external forces such as scratching, trauma, infection, or the healing process. The distinction between a primary and secondary lesion is not always clear.

Click any of the images below to view them in a higher resolution.

This is an accordion element with a series of buttons that open and close related content panels.

Scale

A macule is a change in the color of the skin. It is flat, if you were to close your eyes and run your fingers over the surface of a purely macular lesion, you could not detect it. A macule greater than 1 cm. may be referred to as a patch.

The greasy yellow scale on the scalp of this 3-month-old girl is a classic case of seborrheic dermatitis (otherwise known as cradle cap)
The greasy yellow scale on the scalp of this 3-month-old girl is a classic case of seborrheic dermatitis (otherwise known as cradle cap)

Desquamation of fingertips is associated with Kawasaki disease in an 8-year-old boy.
Desquamation of fingertips is associated with Kawasaki disease in an 8-year-old boy.

This scale is in the scalp and on the hairs of a 3-year-old boy with a fungus infection of the scalp, tinea capitis.
This scale is in the scalp and on the hairs of a 3-year-old boy with a fungus infection of the scalp, tinea capitis.

This scale is in the scalp and on the hairs of a 3-year-old boy with a fungus infection of the scalp, tinea capitis. This is a more detailed picture from the same patient as the previous image.
This scale is in the scalp and on the hairs of a 3-year-old boy with a fungus infection of the scalp, tinea capitis. This is a more detailed picture from the same patient as the previous image.

This plaque of tinea corporis (cutaneous fungal infection) is a papulosquamous lesion.
This plaque of tinea corporis (cutaneous fungal infection) is a papulosquamous lesion.

Crust

Crusting is the result of the drying of plasma or exudate on the skin. Please remember that crusting is different from scaling. The two terms refer to different phenomena and are not interchangeable. One can usually be distinguished from the other by appearance alone.

The honey-colored adherent crusts of this peri-oral lesion are classic for impetigo in this young man.
The honey-colored adherent crusts of this peri-oral lesion are classic for impetigo in this young man.

Atrophy

Atrophy is thinning or absence of the epidermis or subcutaneous fat.

This 15-year-old boy has linear areas of atrophy (striae) secondary to chronic systemic steroid administration.
This 15-year-old boy has linear areas of atrophy (striae) secondary to chronic systemic steroid administration.

The dramatic and extensive atrophy in this 17-year-old young woman is the result of advanced graft vs. host disease (the patient also has extensive telangiectasia).
The dramatic and extensive atrophy in this 17-year-old young woman is the result of advanced graft vs. host disease (the patient also has extensive telangiectasia).

Lichenification

“Lichenification” refers to a thickening of the epidermis seen with exaggeration of normal skin lines. It is usually due to chronic rubbing or scratching of an area.

This 13-year-old girl with very pruritic scabies has lichenification of the skin of the web spaces between her fingers.
This 13-year-old girl with very pruritic scabies has lichenification of the skin of the web spaces between her fingers.

Erosions

Erosions are slightly depressed areas of skin in which part or all of the epidermis has been lost.

The extensive erosions on the leg of this 18-year-old woman are the consequences of a self-inflicted chemical burn.
The extensive erosions on the leg of this 18-year-old woman are the consequences of a self-inflicted chemical burn.

The erosions on the back of the arm of this 4-year-old boy are the base of the unroofed bullae associated with Stevens-Johnson syndrome.
The erosions on the back of the arm of this 4-year-old boy are the base of the unroofed bullae associated with Stevens-Johnson syndrome.

Excoriation

Excoriations are traumatized or abraded skin caused by scratching or rubbing.

Typically very pruritic, swimmers' itch is the source for the excoriations in this very uncomfortable 11-year-old boy.
Typically very pruritic, swimmers’ itch is the source for the excoriations in this very uncomfortable 11-year-old boy.

Fissure

A fissure is linear cleavage of skin which extends into the dermis.

Erosions are slightly depressed areas of skin in which part or all of the epidermis has been lost.

This 5-year-old girl has a fissure at the angle of her lips (and plaques on her tongue) as a consequence of Kawasaki disease.
This 5-year-old girl has a fissure at the angle of her lips (and plaques on her tongue) as a consequence of Kawasaki disease.

This patient has a fissure of the palm of her hand.
This patient has a fissure of the palm of her hand.

Ulceration

Ulcerations occur when there is necrosis of the epidermis and dermis and sometimes of the underlying subcutaneous tissue.

This 3-year-old girl has an extensive ulceration of her lips after having chewed on a live electrical wire.
This 3-year-old girl has an extensive ulceration of her lips after having chewed on a live electrical wire.

Scar

Scars are the permanent fibrotic changes that occur on the skin following damage to the dermis. Scars may have secondary pigment characteristics.

The two photographs of this 12-year-old boy were taken approximately 1-1/2 years apart. They show the clustered vesicles of varicella zoster and the hypopigmented scar tissue which subsequently developed at the site
The two photographs of this 12-year-old boy were taken approximately 1-1/2 years apart. They show the clustered vesicles of varicella zoster and the hypopigmented scar tissue which subsequently developed at the site.

The two photographs of this 12-year-old boy were taken approximately 1-1/2 years apart. They show the clustered vesicles of varicella zoster and the hypopigmented scar tissue which subsequently developed at the site.
The two photographs of this 12-year-old boy were taken approximately 1-1/2 years apart. They show the clustered vesicles of varicella zoster and the hypopigmented scar tissue which subsequently developed at the site.

This 6-year-old boy has hypopigmented scars from a prior varicella infection
This 6-year-old boy has hypopigmented scars from a prior varicella infection

This 4-year-old boy has hyperpigmented scars from a prior varicella infection.
This 4-year-old boy has hyperpigmented scars from a prior varicella infection.

This 13-year-old girl has a scar on the back of her hand where vincristine being given intravenously infiltrated her skin.
This 13-year-old girl has a scar on the back of her hand where vincristine being given intravenously infiltrated her skin.

Eschar

An eschar is a hard plaque covering an ulcer implying extensive tissue necrosis, infarcts, deep burns, or gangrene.

This eschar covers an area of necrosis on the foot of a 15-month-old boy with meningococcemia.
This eschar covers an area of necrosis on the foot of a 15-month-old boy with meningococcemia.

Keloids

Keloids are an exaggerated connective tissue response of injured skin that extend beyond the edges of the original wound.

This 14-year-old boy has a keloid at the site of an old lymph node biopsy site. Note the unaffected scar site on the right side of the keloid.
This 14-year-old boy has a keloid at the site of an old lymph node biopsy site. Note the unaffected scar site on the right side of the keloid.

Petechiae, Purpura, and Ecchymoses

Three terms that refer to bleeding that occurs in the skin are petechiae, purpura, and ecchymoses. Generally, the term “petechiae” refers to smaller lesions. “Purpura” and “ecchymoses” are terms that refer to larger lesions. In certain situations purpura may be palpable. In all situations, petechiae, ecchymoses, and purpura do not blanch when pressed. If there is any question, press on the lesions carefully with a glass slide. Don’t break the slide or cut the patient.

This 7-year-old boy has petechiae from thrombocytopenia secondary to chemotherapy.
This 7-year-old boy has petechiae from thrombocytopenia secondary to chemotherapy.

The palpable purpura on the foot of this nearly 3-year-old boy are associated with the disease Henoch-Schönlein Purpura.
The palpable purpura on the foot of this nearly 3-year-old boy are associated with the disease Henoch-Schönlein Purpura.

The purpura on the back of this 6-year-old boy are known as suction purpura. They are caused by the medical practice of cupping which has its origins in antiquity.
The purpura on the back of this 6-year-old boy are known as suction purpura. They are caused by the medical practice of cupping which has its origins in antiquity.

The purpura and ecchymosis on the skin of this 12-year-old boy were the presenting symptoms of his acute myelogenous leukemia.
The purpura and ecchymosis on the skin of this 12-year-old boy were the presenting symptoms of his acute myelogenous leukemia.