By Gary M. White, MD


Digital Mucous Cyst
Digital Mucous Cyst

Hyperkeratotic Hyponychium

Pterygium Inversum Unguis: Pterygium inversum unguis is a rare nail abnormality in which the distal nail bed adheres to the ventral surface of the nail plate, with obliteration of the distal groove.

Hyperkeratotic Papule(s)

Squamous Cell Carcinoma

Verruca Vulgaris
Verruca Vulgaris

Inflamed (Paronychia)

Paronychia, Acute. This grew out Candida.
Acute Paronychia Caused by Candida

Paronychia, Chronic
Chronic Paronychia

Ingrown Nail
Ingrown Nail

Pyogenic Granuloma. Causes of paronychia with granulation tissue: cetuximab (antepidermal growth factor), protease inhibitors, antiviral agents, Accutane, and some antibiotics [JAAD 2002;45;632]. Here, a patient on isotretinoin with a staph paronychia and a pyogenic granuloma.
Pyogenic Granuloma

Chronic Mucocutaneous Candidiasis

Pemphigus Vulgaris. Pemphigus vulgaris involvement of the nail is rare, although it has been reported to cause paronychia, trachyonychia, nail atrophy, onychomadesis, onycholysis, nail bed erosion, onychoschizia, subungual hemorrhage, nail pitting, nail plate discoloration, cross-ridging of the nail plate, and Beau's lines [CED 1996;21;315].

Antiretroviral Therapy: Periungual inflammation with or without pseudopyogenic granuloma has been described in HIV-positive patients treated with antiretroviral drugs [BJD 1999;140;1165].


Bywaters Lesion. The Bywaters lesion is a necrotic area that forms in the periungual tissue. It is classic for rheumatoid arthritis, but may occur in association with other small-vessel vasculitides.
Bywaters Lesion




Koenen's Tumor

Multicentric Reticulohistiocytosis

Congenital Hypertrophy of the Lateral Nail Folds of the Hallux

Acquired Periungual Fibrokeratoma
Acquired Periungual Fibrokeratoma


Hutchinson's Sign


Paronychia, acute (see above). Either Staph or Candida may be cultured.


Connective Tissue Diseases (here from dermatomyositis)
Periungual Dermatomyositis

Periungual erythema may occur in various connective tissue diseases. For example, dilated and distorted capillary loops alternating with avascular areas occurs in systemic sclerosis and dermatomyositis. This may in rare cases predict the onset of systemic sclerosis in patients with localized morphea. Nailfold bleeding is most characteristic of Raynaud's phenomenon, mixed connective tissue disease, and systemic scleroderma.

Periungual erythema is also a rather nonspecific finding that may be seen in diabetes mellitus, after treatment with cytotoxic agents, in association with severe immunodeficiency (e.g., GvHD, Wiskott-Aldrich syndrome) and in association with HIV infection. See JAAD 1996;35;631.

Red, Scaly

Bazex Syndrome
Bazex Syndrome

Psoriasis of the Periungual Tissue

Squamous Cell Carcinoma. For a picture, see JAAD September 2014 Volume 71, Issue 3, Pages e65–e67.


Pyogenic Granuloma. See Inflammation above.


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