Eczematous dermatitis, skin infections and benign skin tumours are the most common skin problems encountered by a general practitioner.
The diagnosis and treatment are usually based on the patient's history and clinical presentation.
If the diagnosis of a skin tumour remains unclear, taking a biopsy is worthwhile.
Examining the patient
History and a comprehensive clinical examination
Examine also the patient's palms, soles, nails, scalp, oral mucosa and the genital area. Examining these areas will often point towards the right diagnosis.
Family history is important e.g. in atopic dermatitis and psoriasis.
Ask the patient about factors at the workplace and free time that aggravate the condition.
Investigations
Full blood count may give diagnostic clues.
Eosinophilia: atopy, scabies, drug reaction, autoimmune diseases
In the northern countries every third person has seborrhoea Seborrhoeic Dermatitis in the Adult. In Central Europe the percentage is lower and even lower in the Mediterranean area. Diffuse dandruff on the scalp, mainly on the temples (pictures 123). Atopic dermatitis on the scalp of a young adult closely resembles seborrhoeic dermatitis, but the rash occurs also in other typical areas; an exact diagnosis is not necessary as the treatment is the same.
In psoriasis Psoriasis (picture 4), the lesions are well-demarcated and the scaling is thicker.
Lichen simplex nuchae (picture 5) may be a sign of atopy.
Tinea (ringworm) of the scalp Dermatomycoses is rare. At the site of the rash the hair becomes thin and brittle. Fungal cultures can be taken if suspected.
Tinea capitis is more common among patients with dark skin types, particularly in children (e.g. immigrants).
Symmetric dermatitis on the palmar surfaces in a young person is either irritant contact dermatitis or atopic dermatitis.
In an adult patient, the condition usually is irritant contact dermatitis or chronic dermatitis of unknown aetiology (picture 9), rarely allergic contact dermatitis.
Many occupational diseases may only manifest as hand dermatitis - enquire about the patient's employment.
Severe chronic irritant contact dermatitis of the palms (endogenous irritant contact dermatitis of the palms) may in some cases be a sign of excessive alcohol consumption. Smoking may also aggravate it (picture 10).
Unilateral palmar dermatitis is often tinea manuum (picture 11). A fungal culture is indicated.
A sub-form of chronic dermatitis (endogenous irritant contact dermatitis of the palms). More common in older women. The condition is often chronic and persistent. Unknown aetiology.
Psoriasis may only appear on the fingertips.
Myxoid cyst
Myxoid cyst is a wart-like vesicle at the distal joint or in the nail wall of a finger or toe (pictures 14151617). It is often associated with osteoarthritis.
A recurrent cyst can be treated with liquid nitrogen cryotherapy, needle aspiration and cortisone injection or with surgery.
Patchy hyperkeratosis of the palms and soles
Usually a sub-form of chronic irritant contact dermatitis (endogenous irritant contact dermatitis of the palms). Aetiology is unknown. Usually encountered in patients in later adulthood and may occur in families.
Differential diagnosis may include psoriasis (picture 18) and sometimes also allergic contact dermatitis.
Seborrhoeic dermatitis (picture 19) and tinea cruris (jock itch; picture 20) are the most common at this anatomical site. Additionally, intertrigo (chafing of warm, moist apposing skin surfaces) associated with diabetes or obesity is common. Also psoriasis may cause symptoms in the groin (inverse psoriasis; picture 21), but it usually is found also in other skin areas.
Usually circumscribed neurodermatitis (pictures 2728) or nummular eczema (pictures 2930)
A thick reddish-blue patchy lesion may also be chronic hypertrophic lichen planus (picture 31).
Rash on the sole of the foot
Fissured scaling on the balls of the feet and under the toes in children is usually atopic dermatitis (pictures 3233).
Tinea pedis is rare in children under 15 years. In adults, the sites of predilection (pictures 3435) for tinea pedis are under and between the toes.
Scaling across the lower portion of the foot in an adult may be moccasin tinea pedis (picture 36). A fungal culture is indicated.
Unilateral rash increases the likelihood of tinea pedis.
There are two main types of plantar warts Warts (Verruca Vulgaris) (picture 37) : common solitary warts that develop callosities and are therefore painful, and mosaic warts with a diameter of 2-3 mm that spread in a mat-like pattern. They usually occur in large numbers in a single group, more rarely in scattered groups.
A rash of the sole may also be triggered by sweating and maceration alone (picture 38).
Elderly persons often have physiological scaling and skin thickening (hyperkeratoses). Also chronic eczema and corns/calluses are common.
Wilmer EN, Gustafson CJ, Ahn CS ym. Most common dermatologic conditions encountered by dermatologists and nondermatologists. Cutis 2014;94(6):285-92. [PubMed]
Fleischer AB Jr, Herbert CR, Feldman SR ym. Diagnosis of skin disease by nondermatologists. Am J Manag Care 2000;6(10):1149-56. [PubMed]
Ruiz de Luzuriaga AM, Mhlaba J, Roman C. Primary Care of Adult Women: Common Dermatologic Conditions. Obstet Gynecol Clin North Am 2016;43(2):181-200. [PubMed]
Baron SE, Cohen SN, Archer CB ym. Guidance on the diagnosis and clinical management of atopic eczema. Clin Exp Dermatol 2012;37 Suppl 1():7-12. [PubMed]
Hahnel E, Lichterfeld A, Blume-Peytavi U ym. The epidemiology of skin conditions in the aged: A systematic review. J Tissue Viability 2017;26(1):20-28. [PubMed]