Seborrheic Keratosis Differential Diagnosis Table

Seborrheic Keratosis Differential Diagnosis Table:

It is a benign epidermal tumor. Seborrheic keratosis is common in the elderly. It appears as a slow-growing tumor, which is characterized by a waxy, dull, and verrucous surface with a distinctive “stuck-on” appearance. It varies from light depigmented flat to dark bumpy rough lesions. Seborrheic keratosis thickens with time. Seborrheic keratosis is usually asymptomatic. It is diagnosed by skin biopsy or dermascope.

How to Distinguish Seborrheic Keratosis from Other Diseases

Distinguish Basal Cell Carcinoma from Seborrheic Keratosis – Diagnosis

Basal cell carcinoma (BCC) is a malignant tumor.

• Basal cell carcinoma appears from sun-damaged skin and is smooth, but seborrheic keratosis has a waxy, wart-like appearance and is rough.
• Basal cell carcinoma is amelanotic with pink or flesh-colored, but seborrheic keratosis is pigmented and brown-colored.

“Skin excisional biopsy and dermascope are used for differentiation.”

Distinguish Malignant Melanoma from Seborrheic Keratosis – Diagnosis

Malignant Melanoma is a malignant alteration that arises from melanocyte cells.

• Ulceration, itching, and bleeding are common in malignant melanoma, but absent in seborrheic keratosis.

“Malignant melanoma and Seborrheic keratosis are differentiated by ABCDE test and excisional skin biopsy.”

Distinguish Nevus from Seborrheic Keratosis – Diagnosis

Nevus (mole) is a pigmented benign lesion emerging from melanocytes.

• Nevus is congenital, but seborrheic keratosis appears in the elderly.
• Nevus is flat with black or brown in color, while seborrheic keratosis is rough, bumpy, and has a “stuck-on” appearance.

Distinguish Condylomata Acuminata from Seborrheic Keratosis – Diagnosis

Condylomata acuminata is a sexually transmitted human-papillomavirus (HPV) infection.

• Condylomata acuminata appears as warts only along the anogenital area (anus and genitals), unlike seborrheic keratosis, which does not appear in the anogenital area.

“PCR (gene testing) and colposcope are used for differentiation.”

Distinguish Actinic Keratosis from Seborrheic Keratosis – Diagnosis

Actinic Keratosis is a pre-malignant cutaneous tumor due to extensive sun exposure.

• Actinic keratosis appears on the sun-exposed areas only, unlike seborrheic keratosis, which is not triggered by sun exposure.
• Actinic keratosis has a skin texture, while seborrheic keratosis has a wart-like and rough texture.

“Biopsy and dermascope are used for differentiation.”

Distinguish Squamous Cell Cancer from Seborrheic Keratosis – Diagnosis

Squamous Cell cancer is a malignant tumor.

• Squamous cell cancer appears on the sun-exposed areas only, unlike seborrheic keratosis, which is not triggered by sun exposure.
• Squamous cell cancer is characterized by flat inflamed, flesh-colored lesions, but seborrheic keratosis has brown to black colored lesions with a rough and bumpy verrucous appearance.
• Squamous cell cancer is found in sun-damaged skin (such as arms, face, and scalp), but seborrheic keratosis is found on the back and trunk only.

“Skin biopsy is used for differentiation.”

Distinguish Lentigo Maligna from Seborrheic Keratosis – Diagnosis

Lentigo Maligna is a malignant lesion.

• Lentigo Maligna appears on the neck and head, while Seborrheic Keratosis appears on the back and trunk.

“RCM (reflectance confocal microscope) and dermascope are used for differentiation.”

Distinguish Melanocytic Nevus from Seborrheic Keratosis – Diagnosis

Melanocytic Nevus, “freckles,” is a non-cancerous malformation arising from melanin-producing cells, which is harmless.

• Melanocytic nevus is congenital, while seborrheic keratosis is found in the elderly.

“Dermascope is used for differentiation.”

Distinguish Hemangiomas from Seborrheic Keratosis – Diagnosis

Hemangiomas, “strawberry marks,” is an alteration in endothelial cells’ proliferation.

• Hemangiomas are congenital or occur in infancy, while seborrheic keratosis is found in the elderly.
• Hemangiomas have a distinctive voluminous elevated red-purple lump with blood vessels’ visibility, but seborrheic keratosis has a wart-like appearance with brown to black color.

“Dermascope is used for differentiation.”

Distinguish Dermatosa Papulosa Nigra from Seborrheic Dermatitis – Diagnosis

Dermatosa Papulosa Nigra (DPN) is a benign epidermal growth.

• Dermatosa Papulosa Nigra is found on the neck and face, while seborrheic keratosis is found on the back and trunk.

“Seborrheic keratosis and Dermatosa papulosa nigra are hardly differentiated, but dermatosa papulosa nigra affects darker skin tones, while seborrheic keratosis affects light and pale skin tones.”

Distinguish Skin Tags from Seborrheic Keratosis – Diagnosis

Skin tags are benign cutaneous growth with genetic predisposition.

• Skin tags have a soft texture and hang over a thin stalk, while seborrheic keratosis has a rough texture and a “stuck-on” appearance.
• Skin tags are associated with underlying conditions such as obesity or diabetes, while seborrheic keratosis is not associated with an underlying condition.

“Lab tests (blood glucose level and lipid profile) and dermascope are used for differentiation.”

Seborrheic Keratosis Red Flags and Treatments

Although Seborrheic Keratosis is asymptomatic and non-malignant, sometimes a sudden eruption of chronic, painful, pruritic multiple lesions of seborrheic keratosis may appear, indicating a condition termed as “Leser-Trelat” signs. Leser-Trelat indicates an internal gastrointestinal or pulmonary malignancy.

The treatment of choice should be individualized, taking into consideration tumor thickness, size, and skin type. In case of malignancy susceptibility, the tumor must be biopsied and removed. Cryotherapy, shave ablation, and laser are found to be effective ways for treatment.